aggressive token saving attempts

The tab bar's row-2 summary was painted only for the active tab. Add a
per-child summaryTextFor/summaryRawFor helper (active variants now
delegate to it), carry each tab's childID on its tabRect, and loop over
all visible tabs so each renders its own summary under its column.
Layout is unchanged (still 3 rows); narrow tabs clip as before.

Resolves the per-tab summary TODO item.

.gitea/workflows/release.yml

@@ -11,14 +11,19 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-go@v5
+      - uses: jdx/mise-action@v2
         with:
-          go-version-file: go.mod
           cache: true
 
-      - uses: mlugg/setup-zig@v1
+      - name: Cache Go modules
+        uses: actions/cache@v4
         with:
-          version: 0.15.2
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
 
       - name: Build libghostty-vt
         run: make deps

.gitignore

@@ -7,4 +7,5 @@ spike-report-*.txt
 /bin/
 /spike
 /.worktrees/
+/.claude/worktrees/
 internal/harness/.artifacts/

.mise.toml

@@ -0,0 +1,10 @@
+# mise config — `mise install` provisions the tools `make deps` needs.
+#
+# libghostty-vt is built from a pinned upstream Ghostty commit; that
+# commit's build.zig.zon pins minimum_zig_version = 0.15.2. We match
+# it here so contributors don't have to puzzle out the version from
+# a deep upstream file. The go pin matches go.mod so CI and local
+# builds use the same toolchain.
+[tools]
+zig = "0.15.2"
+go = "1.26.3"

CHANGELOG.md

@@ -7,6 +7,330 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ## [Unreleased]
 
 ### Added
+- MCP clients can now call `scratchpad_delete` with a scratchpad name
+  to remove a shared project scratchpad.
+
+### Changed
+- The tab bar now shows each visible agent tab's own summary instead
+  of only rendering the focused tab's summary.
+- `get_process_output` now returns aggressively canonical terminal text
+  by default, removing ANSI/control noise, decorative borders, duplicate
+  status churn, and volatile progress/timer fragments; raw PTY bytes are
+  opt-in with `raw:true`.
+- MCP responses now use slimmer defaults: tool-call JSON is no longer
+  duplicated into text content, large output and scratchpad reads are
+  capped with truncation metadata, and `whoami` / `get_project_status`
+  only include full tool lists when `include_tools` is requested.
+
+### Fixed
+- Injected agent input now sends the submit Enter as a separated,
+  settled keystroke so messages reliably submit instead of sometimes
+  sitting unsent in the composer.
+- Codex agents are no longer reported idle while a turn is still
+  running.
+- Slow MCP tool calls such as `wait_for_pattern` no longer block later
+  tool calls on the same MCP connection.
+- Closing an agent now escalates from SIGTERM to SIGKILL when needed,
+  so agents that ignore SIGTERM disappear from the running tab bar
+  after one Close action while keeping their exited pane readable.
+- Sidebar timer indicators now repaint as their visible countdown
+  value changes, so labels progress from minutes to seconds without
+  waiting for unrelated terminal output or focus changes.
+- Raw terminal focused actions now show a single `Close` row instead
+  of separate stop/delete-style lifecycle choices that did the same
+  thing for ephemeral terminal panes.
+- Restarting a process from the palette now restores the focused pane
+  and host chrome before waiting for the old process to exit, so the
+  tab bar and sidebar do not disappear during slow restarts.
+- Deleting the focused scratchpad now moves focus to another
+  scratchpad when one exists, or back to a running terminal/agent
+  instead of dropping into the empty state.
+- Multiline paste into raw terminal and command panes no longer pays
+  the agent-specific per-Enter delay, making large pasted input arrive
+  as one PTY write outside Claude/Codex/OpenCode panes.
+
+## [0.0.7] - 2026-05-18
+
+### Added
+- The top tab bar now prefixes each agent tab's label with its
+  idle-state glyph (✕ error, ? permission, ◐ thinking, ○ idle, ●
+  working), matching the sidebar's vocabulary so the state of every
+  open agent is visible without opening or focusing each tab.
+
+### Changed
+- Built-in agent presets (`claude`, `codex`, `opencode`) now live in
+  memory and user preset files merge over them by name instead of
+  patterm writing default preset files into `$XDG_CONFIG_HOME`. Add
+  `"disabled": true` in a matching user preset to hide a built-in.
+- Generated MCP config files for agent launches now live under the
+  runtime agent directory instead of `$XDG_CONFIG_HOME/patterm/mcp`.
+- Auto-summarization settings now save as soon as a changed row is
+  applied, including cadence/provider/toggle changes and model edits,
+  without requiring a separate save step.
+- The Agents / Auto-summarization settings screen no longer shows
+  explicit Save, Cancel, or Back rows, and its footer copy no longer
+  describes a separate save/cancel flow.
+- Auto-summarization setting rows now visually separate grey labels
+  from regular-colour values.
+- The active-thread summary in the tab bar is now constrained to the
+  active tab's width instead of spanning the whole top row.
+- Sidebar summary text now wraps from the full summary text instead of
+  using an ellipsized single-line value.
+
+### Fixed
+- Claude permission prompts are now detected from the rendered pane as
+  well as the recent output tail, so the sidebar marks the pane as
+  waiting for permission even while `Calling patterm...` continues to
+  repaint.
+- Removed the redundant "Back to Settings" row from the
+  Agents / Auto-summarization settings screen.
+- Pending `timer_*` entries are now cancelled when their owning or
+  watched child is closed via `close_process`, preventing stale
+  timer bodies from being re-delivered to the orchestrator pane
+  after the work has already been handled.
+
+## [0.0.6] - 2026-05-15
+
+### Changed
+- Toast notifications now reserve three content rows and word-wrap
+  the message body inside the box, replacing the previous
+  single-line+ellipsis layout. The `Ctrl-N · N more` inline hint is
+  gone; instead the host status strip surfaces a `Ctrl-N · dismiss`
+  hint, shown only while a notification is on screen so the chord
+  doesn't advertise itself when it has nothing to dismiss.
+
+### Fixed
+- Auto-summary no longer fails immediately with `codex summarizer:
+  error: unexpected argument '--ask-for-approval' found`. The codex
+  CLI dropped that flag; we now rely on `--sandbox read-only` (which
+  already implies no approvals) instead of passing it.
+- Toast box no longer flickers / half-erases while the focused
+  child (claude, codex, opencode, etc.) repaints its TUI. The
+  overlay is now stitched onto the end of the per-chunk PTY write
+  under `outMu`, and wrapped in DECSET 2026 (synchronized output)
+  brackets so terminals that support it batch the child's redraw +
+  the box paint into a single frame instead of racing cell-by-cell.
+
+## [0.0.5] - 2026-05-15
+
+### Changed
+- Replaced the single-slot status-line "flash" with a stackable toast
+  surface anchored at the top-right of the focused pane. `flashError`,
+  `flashTransient`, and MCP `request_human_attention` now push onto
+  the toast stack (cap 5, oldest drops). Toasts persist until
+  dismissed with `Ctrl-N`, or cleared via the new
+  "Clear notifications" palette command. The status line no longer
+  shows the `[!]` prefix.
+- `Ctrl-N` is consumed by the host only when there is a toast to
+  dismiss; an empty stack lets `Ctrl-N` pass through to the focused
+  child so readline / nano / emacs / opencode keep their bindings.
+- Command palette is calmer when something is focused. Focused-section
+  rows now read as bare verbs (`Rename`, `Close`, `Stop`, `Restart`,
+  `Delete`, `Edit`) instead of repeating the focused name (`Close
+  agent: codex`); the title bar's `on: codex` / `pad: notes.md`
+  carries the subject. Fuzzy queries still match the dropped context
+  through the row hint (e.g. typing `close codex` still finds the
+  Close row).
+- Dashed `── Focused ──` / `── Open ──` / `── Spawn ──` section
+  banners are gone. Sections are separated by a single blank spacer
+  row, so the action labels themselves carry the visual weight.
+- The Open section no longer lists a `Switch to <current>` row for
+  the pane you're already focused on.
+
+## [0.0.4] - 2026-05-15
+
+### Changed
+- Release workflow (`.gitea/workflows/release.yml`) now provisions
+  Zig and Go through `jdx/mise-action@v2`, reading the versions from
+  `.mise.toml` (zig 0.15.2, go 1.26.3). Both toolchains were
+  previously installed via `mlugg/setup-zig` and `actions/setup-go`,
+  whose mirror chase / GitHub fetch combined for ~8 minutes per run
+  before any patterm code compiled. mise pulls each tool once and
+  caches the install dir, so subsequent runs hit the cache instead of
+  re-downloading. `make deps` still resolves zig via `mise which zig`
+  with a PATH fallback; `go.mod` already pinned `go 1.26.3`, so the
+  new `go` entry in `.mise.toml` just keeps CI and local builds on
+  the same toolchain.
+- A Go module/build cache step (`actions/cache@v4`, keyed on
+  `go.sum`) was added so `go build` doesn't re-download dependencies
+  on every tag push.
+
+## [0.0.3] - 2026-05-15
+
+### Added
+- Auto-summarization for top-level agent tabs. patterm now loads
+  `$XDG_CONFIG_HOME/patterm/settings.json`, enables Codex-based
+  summaries by default (`gpt-5.4-mini`; OpenCode defaults to
+  `opencode-go/minimax-m2.7`), and can run Codex, OpenCode, or opt-in
+  Claude summarizers with configurable model names. Summary
+  attempts are armed by meaningful human input, wait for recent output
+  to go quiet, and respect a minimum cadence so unchanged tabs are not
+  summarized on a timer. The active thread summary appears under the
+  top tab title and in the sidebar below the Agent Tree section.
+- Settings overlay reachable from the command palette via
+  `Open Settings`. The searchable Settings picker opens
+  `Agents / Auto-summarization`, where users can enable/disable
+  summaries, choose provider, edit provider model names, cycle cadence,
+  test the selected summarizer (`patterm okay`), summarize the current
+  top-level agent immediately, and explicitly save or cancel draft
+  settings changes. Cadence choices match Solo: `15s`, `30s`, and
+  `1m`; the value is a minimum quiet/activity gap before another
+  summary attempt for the same top-level agent, not a background
+  periodic timer.
+
+### Changed
+- Command palette UX overhaul. The single flat list grew section
+  bands (`── Focused ──`, `── Open ──`, `── Spawn ──`, `── Quit ──`)
+  so the rows are scannable at a glance; cursor navigation skips
+  the dim header rows transparently. A chip strip — `[All] Open
+  Spawn Close` — sits below the query line and tracks the active
+  macro filter; `Tab` / `Shift-Tab` cycle through the chips, and
+  the typed-prefix macros (`sw `, `sp `, `k `) still work and now
+  collapse the whole prefix on a single backspace instead of
+  leaving a stray `sw` behind. The title bar surfaces the current
+  focus subject (`on: <child>` / `pad: <name>`) so the user knows
+  which Focused row is targeting what. The duplicate global Close
+  list is gone — close is reachable via the Focused-section action,
+  the `k ` macro / `[Close]` chip, or the new `Ctrl-X` inline close
+  on a Switch row. The "(current)" marker on the focused Switch row
+  became a leading `▶`. The empty-state hint now reads `no matches
+  · ⌫ to widen` instead of bare `no matches`. The middle divider
+  shows a `▼ N more` / `▲ N above` scroll indicator when the list
+  overflows, and the footer carries a `cursor/total` counter.
+- Spawn verbs are unified on **Spawn**: `Run process: …` →
+  `Spawn process: …`, `New Terminal` → `Spawn terminal`, and the
+  freeform-form row is now `Spawn process… (custom)` so the
+  trailing ellipsis still signals it opens a form.
+- Filtering switched from binary fuzzy-include to scored ranking.
+  Prefix matches beat word-boundary matches beat substring matches
+  beat scattered-fuzzy matches; ties fall back to section order so
+  a Focused-section hit always outranks an equally tight Spawn
+  hit. The matched characters in the rendered label render in
+  accent+bold so the user can see why a row matched.
+- Rename forms split the long subject (`scratchpad:
+  some-really-long-name.md`) onto its own dim row above the input
+  so the title bar no longer truncates with an ellipsis when the
+  subject name is wide.
+- New palette accelerators: `Alt-1` … `Alt-9` quick-pick the Nth
+  visible row, `Home` / `End` jump to first / last selectable row,
+  `?` (with empty query) opens an inline keybinding cheat-sheet
+  which any further keystroke dismisses, and `Ctrl-R` inside the
+  Spawn-process form toggles "Relaunch on exit" without leaving
+  the command field.
+
+### Fixed
+- Error/status flashes now restore the currently focused pane instead
+  of drawing the empty-state hint over a running agent or process.
+- Release workflow (`.gitea/workflows/release.yml`) now uses
+  `mlugg/setup-zig@v2` instead of the deprecated `@v1`. v1 hard-coded
+  the pre-0.14 tarball name (`zig-linux-x86_64-<ver>.tar.xz`), so
+  every mirror and the official `ziglang.org/builds` returned 404 for
+  Zig 0.15.2 and the v0.0.1 / v0.0.2 tag pushes never produced a
+  release asset. v2 uses the post-0.14 `zig-x86_64-linux-<ver>.tar.xz`
+  layout, so the runner can fetch Zig and build patterm.
+- Typing into a focused child while its emulator viewport is
+  scrolled up into scrollback history now auto-snaps the viewport
+  back to the live area. Previously the keystroke reached the
+  child PTY but the input box was off-screen below the visible
+  region, so it looked like typing did nothing. Wheel scrolling
+  and Ctrl-B are unchanged; only forwarded keystrokes snap.
+- Top tab bar now keeps the top-level agent's tab highlighted
+  when focus is on one of its sub-agents (or on a Processes pane
+  entry, matching the existing agent-tree behavior). Previously
+  the tab would lose its highlight as soon as you stepped into a
+  child agent, even though you were still within that thread.
+
+### Changed
+- MCP tool descriptions and `help('coordination')` /
+  `help('readiness')` now spell out that a sub-agent's reply to
+  `send_message` lands in the caller's own pane (tagged
+  `[sub-agent:<name>]`), not in the sub-agent's output. The canonical
+  wait-for-reply pattern — `send_message` → `timer_fire_when_idle_any`
+  on the sub-agent → read your own pane — is now called out on
+  `send_message`, `wait_for_pattern`, both `timer_fire_when_idle_*`,
+  the help topics, and the server-instructions preamble every agent
+  reads at startup. Previously `wait_for_pattern` was the obvious
+  blocking primitive in the catalog, and agents routinely called it
+  against the sub-agent for a reply that had already arrived in their
+  own pane, deadlocking until the wait timed out. No behaviour
+  changes; descriptions only.
+- Agent-initiated `spawn_agent` and `spawn_process` MCP calls no
+  longer steal viewport focus from the currently active tab. The
+  new child still appears in the sidebar and tab bar; switch to it
+  explicitly via the palette or `select_process`. Palette-initiated
+  spawns and persistence restores are unchanged — they still auto-
+  focus the new pane.
+- Sidebar rows (Processes, Agent Tree, Scratchpads) now truncate
+  overflowing names with a trailing `…` instead of spilling into
+  the main viewport. The focused row marquees its name when it
+  overflows — 1 s hold on the head, ~150 ms per cell scroll until
+  the tail is visible, 1 s hold on the tail, snap back. Row
+  position never moves while the marquee animates. When budget is
+  tight, the trailing timer indicator drops before the name
+  ellipses, since the name is the only identifier the row carries.
+
+## [0.0.2] - 2026-05-15
+
+### Added
+- `.mise.toml` pinning `zig = "0.15.2"` (the minimum version the
+  vendored Ghostty commit requires). Contributors run
+  `mise install` once; the Makefile picks up the resulting `zig`
+  binary automatically via `mise which zig` and falls back to
+  PATH when mise isn't available, so the existing build flow
+  still works.
+- ASCII-video stress benchmarks (`internal/app/bench_test.go`):
+  per-frame and per-stream variants at 30 / 60 / 120 fps targets,
+  three workload fixtures (8-colour cells, 24-bit truecolor cells,
+  and a Bad-Apple-style 1-bit pattern). Each stream benchmark
+  reports `µs/frame`, an achievable `fps_ceiling`, and `budget_pct`
+  so you can read off "do we hit N fps?" directly. A matching
+  Pipeline_ASCIIVideo_* set includes libghostty-vt's em.Write CGO
+  and an io.Discard stdout write so the FPS claim reflects the
+  whole pipeline, not just the renderer.
+- MCP `initialize.instructions`, the `spawn_agent` tool description
+  (visible to LLMs via `tools/list`), and the `help('spawning')`
+  topic now spell out — in the three places vendor TUIs actually
+  consult — that the connected `patterm` MCP server is the only
+  correct way to drive the host. Anti-patterns called out by name:
+  (a) trying to launch `patterm` / `patterm mcp-stdio` themselves,
+  (b) piping JSON-RPC into the per-PID Unix socket via `perl` /
+  `nc` / `socat` / `curl`, and (c) shelling out to `claude` /
+  `codex` / `opencode` to start a peer. Each of those bypasses
+  caller identity, so a sub-agent spawned that way reads back as
+  a stray top-level tab instead of a child under the spawning
+  agent. Codex was hitting (b) and (c) in practice — this is the
+  fix.
+- `--debug[=DIR]` flag captures detailed run artefacts for offline
+  analysis: a verbose `patterm.log` (the existing `PATTERM_DEBUG_LOG`
+  stream), an `events.jsonl` lifecycle log (spawn / exit / idle-state
+  changes with timestamps), and per-child `<id>.raw` files containing
+  the raw PTY byte stream. With no argument, the dated subdir
+  `$XDG_STATE_HOME/patterm/debug/YYYYMMDD-HHMMSS` is used; pass an
+  explicit path to override. All output goes to files — stdout/stderr
+  are untouched.
+- `--profile[=DIR]` flag captures pprof data plus concrete
+  performance counters for performance work: `cpu.pprof` (running
+  for the lifetime of the session), plus `heap.pprof` and
+  `goroutine.pprof` snapshots written on shutdown; alongside them,
+  a per-hot-path metrics tracker writes `metrics.jsonl` (one row
+  per second with chunk/byte rates, per-stage mean and max
+  latencies, and cache hit rates) plus a final `metrics.json`
+  aggregate and a human-readable `summary.txt` on exit.
+  Instrumented hot paths: `OnPTYOut`, viewport `renderer.Render`,
+  host stdout writes, libghostty-vt `emulator.Write` / `Title`,
+  sidebar / tab bar / status line draws (with cache-hit
+  accounting), snapshot replays, and the chrome ticker (so you can
+  see how often it fires with nothing to do). Defaults to
+  `$XDG_STATE_HOME/patterm/profile/YYYYMMDD-HHMMSS`. All
+  diagnostics (startup, errors) are written to `profile.log`
+  inside the dir, never to stdout/stderr.
+- Renderer benchmark suite (`internal/app/bench_test.go`). Three
+  workload fixtures — plain ASCII, SGR-styled lines, and a
+  ratatui-style cursor-shuffling burst — plus an OSC-gate
+  micro-benchmark. Run via `go test -bench=. -benchmem
+  ./internal/app/`. Gives a stable reference for the per-chunk
+  cost of the viewport renderer so future changes can be compared
+  apples-to-apples.
 - "New Terminal" entry in the command palette spawns a bare interactive
   `$SHELL` pane (kind `terminal`). Unlike "Run process: …" presets,
   which are session-persistent and reachable via `restart_process`,
@@ -120,6 +444,41 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   renders the canonical `--flag` form.
 
 ### Fixed
+- `make deps` now builds libghostty-vt with `-Doptimize=ReleaseFast`
+  instead of zig's silent `Debug` default, and resolves `zig`
+  through `mise` when a project `.mise.toml` pins it. The
+  default-Debug build shipped an unoptimised CSI/SGR parser that
+  ate 16-29 ms per 30-70 KiB full-screen frame in benchmarks,
+  capping the entire PTY-to-host pipeline at 34-63 fps. After the
+  rebuild the same pipeline runs at **930-2030 fps**: 27-32× the
+  prior throughput, and 7-16× margin over 120 fps for full-screen
+  truecolor ASCII video. Static library size drops from 33 MiB to
+  13 MiB. Override with `make deps GHOSTTY_VT_OPTIMIZE=Debug` only
+  when debugging the upstream library itself. Apply on existing
+  checkouts with `mise install && make clean-deps && make deps`.
+- Long claude session resume (and codex steady-state rendering) is
+  noticeably faster. Two costs that scaled per-PTY-chunk are now
+  deferred or short-circuited: (1) `drawSidebar()` used to run
+  synchronously for every chunk that scrolled — on a session
+  resume where every chunk scrolls, this rebuilt the full sidebar
+  string hundreds of times for a frame that was almost always
+  cache-equal. The sidebar now signals dirty and the chrome ticker
+  (60 Hz) handles the repaint. (2) `pumpChild` polled the
+  emulator's OSC title after every PTY chunk via CGO, even for
+  chunks (the common case under codex/ratatui) that carry no OSC
+  bytes at all. The poll is now gated on a containsOSC scan over
+  the chunk.
+- Click-and-drag text selection from alt-screen TUIs (codex in
+  particular) now works. Patterm used to keep host SGR mouse
+  reporting armed continuously, which forced the host terminal to
+  forward every click as an escape sequence and prevented native
+  selection. The host's mouse mode now follows the focused child's
+  screen side: primary-screen children keep mouse armed (so wheel
+  scrollback works), alt-screen children get host mouse disabled by
+  default. Alt-screen TUIs that need mouse events (vim, less, etc.)
+  re-enable mouse-mode themselves; the viewport renderer forwards
+  those toggles to the host while the child is on alt. Leaving alt
+  re-arms host mouse reporting so wheel scrollback resumes.
 - Exited terminal panes (kind `terminal`, including those launched via
   the new "New Terminal" palette entry or MCP `spawn_process` with
   `kind=terminal`) are now removed from the session and the Processes

Makefile

@@ -20,10 +20,30 @@ $(SOURCE)/.git/HEAD:
 
 deps-fetch: $(SOURCE)/.git/HEAD
 
+# Zig's `standardOptimizeOption` defaults to .Debug when no
+# -Doptimize is passed, which makes libghostty-vt's CSI/SGR parser
+# an order of magnitude slower — truecolor full-screen frames spend
+# ~16-29 ms each in em.Write under Debug (see
+# internal/app/bench_test.go BenchmarkEmulator_Write_*), which caps
+# the full PTY-to-host pipeline at ~60 fps. ReleaseFast is the
+# right default for the shipped artefact. Override with
+# `make deps GHOSTTY_VT_OPTIMIZE=Debug` when you actually want a
+# debug build of the upstream lib.
+GHOSTTY_VT_OPTIMIZE ?= ReleaseFast
+
+# Resolve zig via the project's mise pin (.mise.toml) when available,
+# falling back to whatever's on PATH. mise keeps the zig version in
+# lockstep with what the pinned ghostty commit requires; without it,
+# contributors have to chase the version requirement themselves.
+ZIG := $(shell command -v mise >/dev/null && mise which zig 2>/dev/null || command -v zig 2>/dev/null)
+
 $(INSTALL)/lib/libghostty-vt.a: $(SOURCE)/.git/HEAD
-	@command -v zig >/dev/null || { echo "ERROR: zig not on PATH (need >=0.15.2 to build libghostty-vt)"; exit 1; }
-	@echo ">> building libghostty-vt with zig"
-	@cd $(SOURCE) && zig build -Demit-lib-vt --prefix $(INSTALL)
+	@if [ -z "$(ZIG)" ]; then \
+		echo "ERROR: zig not available. Run \`mise install\` (see .mise.toml — needs zig 0.15.2) or install zig manually."; \
+		exit 1; \
+	fi
+	@echo ">> building libghostty-vt with $(ZIG) (optimize=$(GHOSTTY_VT_OPTIMIZE))"
+	@cd $(SOURCE) && $(ZIG) build -Demit-lib-vt -Doptimize=$(GHOSTTY_VT_OPTIMIZE) --prefix $(INSTALL)
 	@test -f $(INSTALL)/lib/libghostty-vt.a || { echo "ERROR: expected static lib at $(INSTALL)/lib/libghostty-vt.a"; exit 1; }
 	@echo ">> libghostty-vt installed under $(INSTALL)"
 

SPEC.md

@@ -39,7 +39,7 @@ The tool is one Go process that owns: the TUI, all PTYs, vt-emulated grids, sess
 
 ## 3. Project state layout
 
-Scratchpads (user data) live under `$XDG_DATA_HOME`; presets and config live under `$XDG_CONFIG_HOME`.
+Scratchpads (user data) live under `$XDG_DATA_HOME`; user-authored preset overlays and config live under `$XDG_CONFIG_HOME`.
 
 ```
 $XDG_DATA_HOME/patterm/
@@ -53,12 +53,12 @@ $XDG_DATA_HOME/patterm/
             └── <agent-written>.md
 
 $XDG_CONFIG_HOME/patterm/
-├── config.json                # global settings (theme, default keymap, etc.)
+├── settings.json              # global settings, written only after the user changes settings
 └── presets/
     ├── agents/
-    │   ├── claude.json        # ships as default
-    │   ├── codex.json         # ships as default
-    │   ├── opencode.json      # ships as default
+    │   ├── claude.json        # optional overlay for built-in claude
+    │   ├── codex.json         # optional overlay for built-in codex
+    │   ├── opencode.json      # optional overlay for built-in opencode
     │   └── <user-defined>.json
     └── processes/
         ├── dev.json           # e.g. { "name": "bun run dev", "argv": ["bun", "run", "dev"] }
@@ -66,7 +66,7 @@ $XDG_CONFIG_HOME/patterm/
         └── <user-defined>.json
 ```
 
-Both preset directories are scanned at startup; every file found becomes a palette entry ("Spawn agent: claude", "Run process: bun run dev", …). Presets are project-agnostic in v1 — the same set is available in every project. Per-project overrides can be added later.
+patterm always has built-in agent presets for `claude`, `codex`, and `opencode`. User preset files are scanned at startup and merged into matching built-ins by `name`, or added as standalone custom presets when the name is new. A matching file with `"disabled": true` hides a built-in. Startup does not write default preset files. Presets are project-agnostic in v1 — the same set is available in every project. Per-project overrides can be added later.
 
 Project key = `sha256(realpath(project_dir))[:16]`. Used only as a scratchpad directory name — there is no daemon to look up.
 
@@ -121,7 +121,7 @@ Scratchpads and command-preset trust grants persist across runs. Sessions and ch
 Almost all application functions are driven through a single command palette opened with `Ctrl-K`. The palette is a fuzzy-searchable list of commands, scoped to whatever makes sense for the current focus. Two kinds of entries appear:
 
 - **Built-in commands** — "Switch to session…", "Focus pane…", "Take input control", "Release control to orchestrator", "Open scratchpad…", "Kill child…", "Quit", etc.
-- **Preset commands** — one entry per file under `$XDG_CONFIG_HOME/patterm/presets/`. Agent presets surface as "Spawn agent: codex" / "Spawn agent: claude" / …; process presets surface as "Run process: bun run dev" / "Run process: vitest" / …. The label comes from the preset's `name` field; the action is "launch this preset into a new pane."
+- **Preset commands** — one entry per built-in or user-defined preset. Agent presets surface as "Spawn agent: codex" / "Spawn agent: claude" / …; process presets surface as "Run process: bun run dev" / "Run process: vitest" / …. The label comes from the preset's `name` field; the action is "launch this preset into a new pane."
 
 Selecting a preset either launches it immediately (no required args) or opens a sub-palette for optional args — namely an **initial prompt** (agent presets only), which patterm injects into the spawned PTY's input after the agent is ready (§8). The orchestrator equivalent of this — `spawn_agent` / `spawn_process` MCP tools — uses the exact same machinery: pick a preset by name, optionally supply an initial prompt, patterm handles the rest.
 
@@ -365,11 +365,11 @@ Risks acknowledged: the orchestrator's reading of the prompt is a vision/parsing
 
 ## 10. Presets
 
-Presets are user-editable JSON files that describe how to launch something. patterm itself has no hard-coded agent or process types — every spawnable thing is a preset. Two flavours:
+Presets describe how to launch something. patterm has built-in defaults for common agent CLIs, and user-editable JSON files can override, disable, or add presets. Two flavours:
 
 ### Agent presets
 
-`$XDG_CONFIG_HOME/patterm/presets/agents/<name>.json`. Launches a vendor LLM CLI with MCP wired up and the conversation-protocol addendum injected.
+Built-in agent presets launch vendor LLM CLIs with MCP wired up and the conversation-protocol addendum injected. `$XDG_CONFIG_HOME/patterm/presets/agents/<name>.json` can overlay a built-in by `name` or define a new agent preset.
 
 | Field | Purpose |
 |---|---|
@@ -377,17 +377,18 @@ Presets are user-editable JSON files that describe how to launch something. patt
 | `argv` | Full launch argv (e.g. `["claude"]`, `["codex", "--no-tui-banner"]`) |
 | `env` | Env vars to set (merged over inherited env) |
 | `working_dir` | Defaults to the project root |
+| `disabled` | If `true`, hides a built-in preset with the same `name` |
 | `mcp_injection` | How to point this CLI at patterm's stdio proxy. One of: `{ "kind": "flag", "flag": "--mcp-config", "config_path": "..." }`, `{ "kind": "config_file", "path": "~/.codex/config.toml", "merge_key": "mcp_servers" }`, `{ "kind": "env_var", "var": "MCP_CONFIG_PATH" }` |
 | `ready_signal` | How to detect the TUI is ready (default: 1s idle after launch). Override per-CLI if needed. |
 | `chrome_trim_hints` | Optional regexes / row ranges for stripping vendor chrome in grid reads |
 
-Default presets shipped: `claude`, `codex`, `opencode`. Authoring these is per-vendor research — each CLI has its own MCP config conventions, ready states, and TUI chrome. Users can copy and edit them, or add new ones (e.g. a second `claude` preset that launches with a specific model or system prompt file).
+Built-in presets: `claude`, `codex`, `opencode`. Authoring these is per-vendor research — each CLI has its own MCP config conventions, ready states, idle detection, and TUI chrome. Users can add small overlay files for built-ins, disable built-ins, or add new presets (e.g. a second `claude-sonnet` preset that launches with a specific model or system prompt file).
 
 MCP config flow: at startup, for each agent preset, patterm renders a small JSON pointing at its own `mcp-stdio` proxy subcommand (`patterm mcp-stdio --socket <pid-sock> --identity <token>`) into a per-preset temp file. The launch then uses the preset's `mcp_injection` strategy to hand that path to the CLI. The user's global vendor config is never mutated.
 
 ### Process presets
 
-`$XDG_CONFIG_HOME/patterm/presets/processes/<name>.json`. Launches a raw command in a PTY — no MCP, no addendum, no system prompt.
+`$XDG_CONFIG_HOME/patterm/presets/processes/<name>.json`. Launches a raw command in a PTY — no MCP, no addendum, no system prompt. There are no built-in process presets.
 
 | Field | Purpose |
 |---|---|

TODO.md

@@ -1,27 +1 @@
-- [ ] Codex seemed to think that it needed to launch patterm itself to get the mcp working
-- [ ] I cant click and drag to select text from codex
-- [ ] codex uses perl to interact with the socket rather than calling mcp tools
-  - when it _did_ open a sub claude it opened it as a separate tab rather than a sub-agent.
-- [ ] codex rendering is VERY slow
-  - maybe we need to use diffing rather than rendering the entire viewport for performance
-- We should add a --debug and --profile flag, so we can get detailed performance data and full logs of the agent output to be debugged later on.
-  - I don't mind what format this is in, ideally easy for LLMs to understand
-- [ ] Resuming a long claude session takes a couple of seconds for the entire buffer to load in, it looks like it's scrolling down for a couple seconds.
-  - In raw alacritty this is instant, so there's some sort of performance issue with patterm's terminal emulation.
-
-
-# On Hold
-- [ ] There's a unicode <?> being displayed in opencode [ON HOLD]
-  - Investigated 2026-05-14: patterm passes ghostty grapheme codepoints
-    through unchanged (vt/ghostty.go:452-462), so the `<?>` glyph is
-    most likely the *host* terminal's font fallback for opencode's
-    Nerd Font private-use codepoints, not a patterm substitution.
-    Need a concrete reproduction (which codepoint, which host
-    terminal/font) before changing rendering.
-- [ ] After codex rips for like 15 minutes, the terminal becomes quite slow. [ON HOLD / VERIFYING]
-  - 2026-05-14: Perf plan P1-P11 landed (see CHANGELOG). Needs a real
-    long-running codex session to confirm whether the steady-state
-    slowdown is gone or some hotspot remains. Capture a pprof if it
-    still feels slow after ≥15 minutes — the structural drivers the
-    audit named are all addressed, so a remaining symptom is a new
-    one and probably wants fresh profiling.
+- [ ] Pasting into codex is no longer clean, it sends loads of messages rather than one clean paste.

cmd/patterm/main.go

@@ -16,7 +16,10 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"path/filepath"
+	"runtime"
 	"runtime/debug"
+	"runtime/pprof"
 	"time"
 
 	flag "github.com/spf13/pflag"
@@ -49,7 +52,13 @@ func main() {
 	var (
 		projectDir  = flag.String("project", "", "project directory (default $PWD)")
 		showVersion = flag.Bool("version", false, "print version and exit")
+		debugDir    = flag.String("debug", "", "write debug logs + per-child raw PTY output to DIR (auto-picks a dated subdir under $XDG_STATE_HOME/patterm/debug when DIR is omitted)")
+		profileDir  = flag.String("profile", "", "write pprof files (cpu/heap/goroutine) and live perf counters (metrics.jsonl per-second, metrics.json + summary.txt on exit) to DIR (auto-picks a dated subdir under $XDG_STATE_HOME/patterm/profile when DIR is omitted)")
 	)
+	// Allow bare `--debug` / `--profile` with no value — pflag treats
+	// them as boolean-shaped strings, picking a sensible default dir.
+	flag.Lookup("debug").NoOptDefVal = "auto"
+	flag.Lookup("profile").NoOptDefVal = "auto"
 	flag.Parse()
 
 	if *showVersion {
@@ -73,15 +82,104 @@ func main() {
 		die("chdir %s: %v", cwd, err)
 	}
 
+	resolvedDebug, err := resolveDiagDir(*debugDir, "debug")
+	if err != nil {
+		die("debug: %v", err)
+	}
+	resolvedProfile, err := resolveDiagDir(*profileDir, "profile")
+	if err != nil {
+		die("profile: %v", err)
+	}
+
+	stopProfile := startProfile(resolvedProfile)
+	defer stopProfile()
+
 	ctx := context.Background()
 	if err := app.Run(ctx, app.Options{
 		ProjectDir: cwd,
 		ProjectKey: key,
+		DebugDir:   resolvedDebug,
+		ProfileDir: resolvedProfile,
 	}); err != nil {
 		die("%v", err)
 	}
 }
 
+// resolveDiagDir turns the raw flag value into an absolute directory
+// path. Empty string disables the feature. The sentinel "auto" (set by
+// NoOptDefVal on bare flags) picks $XDG_STATE_HOME/patterm/<kind>/<ts>.
+// Any other value is treated as a literal path.
+func resolveDiagDir(raw, kind string) (string, error) {
+	if raw == "" {
+		return "", nil
+	}
+	if raw == "auto" {
+		base := os.Getenv("XDG_STATE_HOME")
+		if base == "" {
+			home, err := os.UserHomeDir()
+			if err != nil {
+				return "", err
+			}
+			base = filepath.Join(home, ".local", "state")
+		}
+		ts := time.Now().Format("20060102-150405")
+		return filepath.Join(base, "patterm", kind, ts), nil
+	}
+	return raw, nil
+}
+
+// startProfile begins a CPU profile under dir and returns a stop func
+// that writes heap + goroutine snapshots before flushing the CPU file.
+// Returns a no-op stop func when dir is empty. All diagnostics are
+// written to <dir>/profile.log — never to stdout/stderr — so the TUI
+// stays uncluttered.
+func startProfile(dir string) func() {
+	if dir == "" {
+		return func() {}
+	}
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return func() {}
+	}
+	logPath := filepath.Join(dir, "profile.log")
+	plog := func(format string, args ...any) {
+		f, err := os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o600)
+		if err != nil {
+			return
+		}
+		defer f.Close()
+		fmt.Fprintf(f, format+"\n", args...)
+	}
+	cpuPath := filepath.Join(dir, "cpu.pprof")
+	f, err := os.Create(cpuPath)
+	if err != nil {
+		plog("cpu open: %v", err)
+		return func() {}
+	}
+	if err := pprof.StartCPUProfile(f); err != nil {
+		plog("cpu start: %v", err)
+		_ = f.Close()
+		return func() {}
+	}
+	plog("profiling started at %s", time.Now().Format(time.RFC3339Nano))
+	return func() {
+		pprof.StopCPUProfile()
+		_ = f.Close()
+		// Heap and goroutine snapshots at exit. Heap captures
+		// steady-state allocation; goroutine catches stragglers
+		// that didn't get cleaned up.
+		runtime.GC()
+		if hf, err := os.Create(filepath.Join(dir, "heap.pprof")); err == nil {
+			_ = pprof.Lookup("heap").WriteTo(hf, 0)
+			_ = hf.Close()
+		}
+		if gf, err := os.Create(filepath.Join(dir, "goroutine.pprof")); err == nil {
+			_ = pprof.Lookup("goroutine").WriteTo(gf, 0)
+			_ = gf.Close()
+		}
+		plog("profiling stopped at %s", time.Now().Format(time.RFC3339Nano))
+	}
+}
+
 func runMCPProxy() {
 	var (
 		socket   = flag.String("socket", "", "path to the running patterm process's MCP socket")

fucked-up-terminal-3.txt

@@ -1,61 +0,0 @@
-                                                                                                        claude                                                                                                         + new │ Processes
-━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━───────│ ─────────────────────────
- - abc1234 if no tag exists yet
-
- 4. Wire version into the release workflow
-
- Update .gitea/workflows/release.yml lines 31-35 to inject the pushed tag:
-
- go build -trimpath \
-   -ldflags="-s -w -X main.version=${{ github.ref_name }}" \
-   -o dist/patterm-${{ github.ref_name }}-linux-amd64 \
-   ./cmd/patterm
-
- github.ref_name is the tag name (e.g. v0.0.1) because the workflow only
- triggers on tags: ['v*'].
-
- 5. Update inline doc comment
-
- cmd/patterm/main.go header comment (lines 5-11) — add the --version form
- to the usage block. SPEC.md/CLAUDE.md already use --, no change needed there.
-
- Out of scope
-
- - Surfacing version in MCP whoami (the hardcoded "version": "0.1.0" in
- internal/mcp/protocol.go:27 is the MCP protocol version, not the patterm
- binary version — leave it).
- - Renaming any existing flags.
- - Adding short forms like -p for --project.
-
- Critical files
-
- - cmd/patterm/main.go — import swap, --version wiring, version var, header comment
- - cmd/patterm/debug_harness.go — import swap
- - Makefile lines 38-39 — VERSION var + ldflags
- - .gitea/workflows/release.yml lines 31-35 — ldflags
- - go.mod / go.sum — add github.com/spf13/pflag
-
- Verification
-
- 1. go build -o ./bin/patterm ./cmd/patterm (without Makefile) → still builds, version reports dev.
- 2. make patterm → ./bin/patterm --version prints patterm v0.0.1 (commit <sha>, built <date>).
- 3. ./bin/patterm -h → help text shows --project string and --version lines.
- 4. ./bin/patterm -project /tmp → pflag rejects with usage error (confirms -- is enforced).
- 5. ./bin/patterm --project /tmp → starts normally.
- 6. ./bin/patterm mcp-stdio --socket /tmp/s --identity x → existing path still works (will fail to connect, but should parse flags fine).
- 7. ./bin/patterm debug-harness --scenario internal/harness/scenarios/spawn_process_via_palette.json → harness still runs.
- 8. go test ./... and go test ./internal/harness/... — both green.
- 9. Push a temporary tag locally and inspect git describe output; confirm release workflow's ${{ github.ref_name }} substitution matches the tag.
-╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
-
- Claude has written up a plan and is ready to execute. Would you like to proceed?
-
- ❯ 1. Yes, and use auto mode
-   2. Yes, manually approve edits
-   3. No, refine with Ultraplan on Claude Code on the web
-   4. Tell Claude what to change
-      shift+tab to approve with this feedback
-
- ctrl-g to edit in VS Code · ~/.claude/plans/flags-in-this-project-vectorized-gosling.md
-
-claude · you have control                                                                                                                                                                   Ctrl-A/D · tabs  ·  Ctrl-W/S · tree  ·  Ctrl-K · palette

internal/app/bench_test.go

@@ -0,0 +1,546 @@
+package app
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/hjbdev/patterm/internal/vt"
+)
+
+// Benchmarks for patterm's hot paths. Run with:
+//
+//	go test -bench=. -benchmem ./internal/app/
+//
+// or target one:
+//
+//	go test -bench=BenchmarkViewportRenderer_PlainASCII -benchmem ./internal/app/
+//
+// The fixtures below model the three workloads we care about most:
+//
+//   - PlainASCII: long-running text output (claude streaming a code
+//     diff, codex outputting a tool result body). Fast-path territory.
+//   - StyledLines: SGR-heavy output (claude/codex chat history with
+//     coloured tokens). State-machine path.
+//   - RatatuiBurst: many short cursor-positioning / SGR transitions in
+//     a tight chunk, matching codex/ratatui's incremental diff
+//     updates.
+//   - SnapshotReplay: full styled-grid replay (focus switch).
+
+// buildPlainASCIIChunk returns a roughly N-byte chunk of pure
+// printable ASCII text with the occasional newline — the cheapest
+// workload, exercises the fast path in viewport_renderer.Render.
+func buildPlainASCIIChunk(n int) []byte {
+	var b strings.Builder
+	b.Grow(n)
+	line := "The quick brown fox jumps over the lazy dog 0123456789 "
+	for b.Len() < n {
+		b.WriteString(line)
+		if b.Len()%80 < len(line) {
+			b.WriteByte('\n')
+		}
+	}
+	return []byte(b.String()[:n])
+}
+
+// buildStyledLinesChunk simulates SGR-heavy output: every word wears
+// a colour, so the renderer breaks out of its fast path on every
+// escape sequence.
+func buildStyledLinesChunk(n int) []byte {
+	var b strings.Builder
+	b.Grow(n)
+	colours := []string{"31", "32", "33", "34", "35", "36"}
+	words := []string{"package", "func", "return", "import", "struct", "type", "const", "var"}
+	i := 0
+	for b.Len() < n {
+		fmt.Fprintf(&b, "\x1b[%sm%s\x1b[0m ", colours[i%len(colours)], words[i%len(words)])
+		if i%10 == 9 {
+			b.WriteByte('\n')
+		}
+		i++
+	}
+	return []byte(b.String()[:n])
+}
+
+// buildRatatuiBurst simulates a single ratatui-style diff frame:
+// CUP, SGR, a few chars, CUP, SGR, a few chars… for a viewport's
+// worth of cells.
+func buildRatatuiBurst(cells int) []byte {
+	var b strings.Builder
+	for i := 0; i < cells; i++ {
+		row := (i / 80) + 1
+		col := (i % 80) + 1
+		fmt.Fprintf(&b, "\x1b[%d;%dH\x1b[3%dm%c", row, col, i%8, byte('A'+(i%26)))
+	}
+	b.WriteString("\x1b[0m")
+	return []byte(b.String())
+}
+
+// BenchmarkViewportRenderer_PlainASCII drives a 16 KiB plain-text
+// chunk through Render once per iteration. Reports ns/op,
+// allocations, and B/op.
+func BenchmarkViewportRenderer_PlainASCII(b *testing.B) {
+	chunk := buildPlainASCIIChunk(16 * 1024)
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(chunk)
+	}
+}
+
+// BenchmarkViewportRenderer_StyledLines exercises the per-byte CSI
+// path on SGR-heavy output. Most claude/codex chat resume traffic
+// looks like this — coloured prose with frequent style toggles.
+func BenchmarkViewportRenderer_StyledLines(b *testing.B) {
+	chunk := buildStyledLinesChunk(16 * 1024)
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(chunk)
+	}
+}
+
+// BenchmarkViewportRenderer_RatatuiBurst measures the worst-case
+// cursor-shuffling workload: full-frame diff updates dominated by
+// CUP + SGR + single-char writes.
+func BenchmarkViewportRenderer_RatatuiBurst(b *testing.B) {
+	chunk := buildRatatuiBurst(80 * 24) // one screenful of cells
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(chunk)
+	}
+}
+
+// BenchmarkContainsOSC measures the OSC-gate fast path used by
+// pumpChild before deciding whether to fire the per-chunk Title()
+// CGO call. Inputs:
+//   - "hot": SGR-styled output without OSC — the common case for
+//     codex/ratatui. We want this near zero.
+//   - "cold": chunk with an OSC sequence in the middle.
+func BenchmarkContainsOSC_NoOSC(b *testing.B) {
+	chunk := buildStyledLinesChunk(8 * 1024)
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = containsOSC(chunk)
+	}
+}
+
+func BenchmarkContainsOSC_WithOSC(b *testing.B) {
+	chunk := append(buildStyledLinesChunk(8*1024), []byte("\x1b]0;new title\x07")...)
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = containsOSC(chunk)
+	}
+}
+
+// BenchmarkRendererThroughput_ReuseInstance approximates real
+// session behaviour: a single viewport renderer fed many chunks in
+// sequence, no per-iteration allocation. Reports a throughput
+// closer to the steady-state OnPTYOut path. Chunks are 4 KiB to
+// match typical PTY read sizes; the renderer is reset every
+// benchmark run.
+func BenchmarkRendererThroughput_ReuseInstance(b *testing.B) {
+	chunks := make([][]byte, 16)
+	for i := range chunks {
+		chunks[i] = buildStyledLinesChunk(4 * 1024)
+	}
+	totalBytes := 0
+	for _, c := range chunks {
+		totalBytes += len(c)
+	}
+	b.SetBytes(int64(totalBytes))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		for _, c := range chunks {
+			_ = vr.Render(c)
+		}
+	}
+}
+
+// Stress workloads — these model the worst things a real session
+// can throw at us. The headline target is "ASCII video": every cell
+// of an 80x40 viewport carries an SGR colour change and a printable
+// character, rendered as one chunk per frame. Real ASCII-video CLIs
+// (ascii-image-converter, asciinema-render, towel.blinkenlights, the
+// Bad Apple meme) hit patterm with exactly this pattern at 24-30 fps
+// for minutes at a time.
+//
+// We synthesise the workload rather than ship a captured corpus so
+// the benchmarks stay deterministic and the repo doesn't carry tens
+// of MiB of fixture data. The encoding is faithful to what those
+// tools actually emit.
+
+// buildASCIIVideoFrame builds a single full-viewport frame with
+// 8-colour SGR per cell (`\x1b[3Nm`). One frame ≈ 30 KiB for an
+// 80x40 viewport, which lines up with what ascii-video tools emit.
+func buildASCIIVideoFrame(cols, rows int) []byte {
+	var b strings.Builder
+	b.WriteString("\x1b[H") // home cursor before the frame starts
+	for r := 0; r < rows; r++ {
+		for c := 0; c < cols; c++ {
+			fmt.Fprintf(&b, "\x1b[3%dm%c", (r+c)%8, byte(' '+(r*c)%(0x7e-' ')))
+		}
+		b.WriteString("\x1b[0m\r\n")
+	}
+	return []byte(b.String())
+}
+
+// buildASCIIVideoFrameTrueColor builds the same frame but with
+// 24-bit RGB SGR (`\x1b[38;2;R;G;Bm`). Every cell is ~20 bytes of
+// escape + 1 byte glyph, so a frame is ≈ 70 KiB. This is what
+// chafa --colors=full and modern terminal video players emit, and
+// it's the heaviest SGR variant the renderer's CSI path sees.
+func buildASCIIVideoFrameTrueColor(cols, rows int) []byte {
+	var b strings.Builder
+	b.WriteString("\x1b[H")
+	for r := 0; r < rows; r++ {
+		for c := 0; c < cols; c++ {
+			rd := (r * 7) % 256
+			gd := (c * 11) % 256
+			bd := ((r + c) * 13) % 256
+			fmt.Fprintf(&b, "\x1b[38;2;%d;%d;%dm%c", rd, gd, bd, byte(' '+(r*c)%(0x7e-' ')))
+		}
+		b.WriteString("\x1b[0m\r\n")
+	}
+	return []byte(b.String())
+}
+
+// buildBadApplePattern builds the simplest possible ASCII video
+// frame: alternating black/white cells (the Bad Apple meme is
+// essentially a 1-bit silhouette video). This is the pattern that
+// stresses the SGR state-machine without exercising truecolor parse
+// — useful for isolating "is the cost in the colour parsing or in
+// the cell-by-cell switching?"
+func buildBadApplePattern(cols, rows int) []byte {
+	var b strings.Builder
+	b.WriteString("\x1b[H")
+	for r := 0; r < rows; r++ {
+		for c := 0; c < cols; c++ {
+			if (r+c)%2 == 0 {
+				b.WriteString("\x1b[37m█")
+			} else {
+				b.WriteString("\x1b[30m█")
+			}
+		}
+		b.WriteString("\x1b[0m\r\n")
+	}
+	return []byte(b.String())
+}
+
+// BenchmarkASCIIVideo_Frame_8Color renders a single full-screen
+// frame as one chunk. The headline number is MB/s — at 30 fps a
+// frame is one PTY chunk every ~33 ms, so this should comfortably
+// stay well under 1 ms.
+func BenchmarkASCIIVideo_Frame_8Color(b *testing.B) {
+	frame := buildASCIIVideoFrame(80, 40)
+	b.SetBytes(int64(len(frame)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(frame)
+	}
+}
+
+// BenchmarkASCIIVideo_Frame_TrueColor renders a single truecolor
+// frame. ~70 KiB per frame. Compare this to the 8-colour number to
+// see how much extra cost the truecolor SGR parse imposes — the
+// `\x1b[38;2;R;G;Bm` form is the longest and most parameter-rich
+// CSI patterm sees in practice.
+func BenchmarkASCIIVideo_Frame_TrueColor(b *testing.B) {
+	frame := buildASCIIVideoFrameTrueColor(80, 40)
+	b.SetBytes(int64(len(frame)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(frame)
+	}
+}
+
+// BenchmarkASCIIVideo_Frame_BadApple is the 1-bit pattern: simplest
+// SGR (two colours, alternating). Isolates the renderer's cell-by-
+// cell SGR cycling cost from the truecolor parse cost.
+func BenchmarkASCIIVideo_Frame_BadApple(b *testing.B) {
+	frame := buildBadApplePattern(80, 40)
+	b.SetBytes(int64(len(frame)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(frame)
+	}
+}
+
+// runStreamBench is the shared body for the per-fps stream
+// benchmarks. It feeds a fixed frame N times through a single
+// renderer instance and reports µs/frame + an achievable-fps
+// ceiling alongside the standard ns/op + MB/s. The fps value in
+// the benchmark name is the *target* — the workload itself doesn't
+// rate-limit; we just decide how many frames make a benchmark op
+// (3 seconds' worth) so steady-state cost dominates warm-up.
+func runStreamBench(b *testing.B, frame []byte, fps int) {
+	frames := fps * 3 // 3 seconds at the target rate
+	totalBytes := int64(len(frame) * frames)
+	b.SetBytes(totalBytes)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		for f := 0; f < frames; f++ {
+			_ = vr.Render(frame)
+		}
+	}
+	nsPerFrame := float64(b.Elapsed().Nanoseconds()) / float64(b.N*frames)
+	b.ReportMetric(nsPerFrame/1000.0, "µs/frame")
+	b.ReportMetric(1e9/nsPerFrame, "fps_ceiling")
+	// budget_pct = how much of the per-frame budget at the target
+	// rate we burn. Under 100 means we can hit the target; over
+	// means we can't.
+	budgetNs := 1e9 / float64(fps)
+	b.ReportMetric(nsPerFrame/budgetNs*100, "budget_pct")
+}
+
+// BenchmarkASCIIVideo_Stream_8Color_30fps / _60fps / _120fps reuse
+// one renderer across (3 × fps) frames. The headline numbers are
+// µs/frame, fps_ceiling (= 1e9 / ns/frame), and budget_pct (=
+// percent of the per-frame budget at the target rate we consume).
+//
+// 30 fps is the typical ASCII-video baseline (towel, chafa, Bad
+// Apple ports). 60 is the "smooth playback" target. 120 is a
+// future-proofing stress level matching modern high-refresh
+// terminals.
+func BenchmarkASCIIVideo_Stream_8Color_30fps(b *testing.B) {
+	runStreamBench(b, buildASCIIVideoFrame(80, 40), 30)
+}
+func BenchmarkASCIIVideo_Stream_8Color_60fps(b *testing.B) {
+	runStreamBench(b, buildASCIIVideoFrame(80, 40), 60)
+}
+func BenchmarkASCIIVideo_Stream_8Color_120fps(b *testing.B) {
+	runStreamBench(b, buildASCIIVideoFrame(80, 40), 120)
+}
+
+// BenchmarkASCIIVideo_Stream_TrueColor_* same set but with the
+// truecolor frames. Compare against the 8-colour numbers to see
+// what the longer `\x1b[38;2;R;G;Bm` parse costs us.
+func BenchmarkASCIIVideo_Stream_TrueColor_30fps(b *testing.B) {
+	runStreamBench(b, buildASCIIVideoFrameTrueColor(80, 40), 30)
+}
+func BenchmarkASCIIVideo_Stream_TrueColor_60fps(b *testing.B) {
+	runStreamBench(b, buildASCIIVideoFrameTrueColor(80, 40), 60)
+}
+func BenchmarkASCIIVideo_Stream_TrueColor_120fps(b *testing.B) {
+	runStreamBench(b, buildASCIIVideoFrameTrueColor(80, 40), 120)
+}
+
+// BenchmarkASCIIVideo_Stream_BadApple_* tracks the 1-bit alternating
+// pattern. Isolates per-cell SGR cycling cost from the truecolor
+// parse cost above — useful when reading the diff between the two
+// stream variants.
+func BenchmarkASCIIVideo_Stream_BadApple_30fps(b *testing.B) {
+	runStreamBench(b, buildBadApplePattern(80, 40), 30)
+}
+func BenchmarkASCIIVideo_Stream_BadApple_60fps(b *testing.B) {
+	runStreamBench(b, buildBadApplePattern(80, 40), 60)
+}
+func BenchmarkASCIIVideo_Stream_BadApple_120fps(b *testing.B) {
+	runStreamBench(b, buildBadApplePattern(80, 40), 120)
+}
+
+// BenchmarkEmulator_Write_8Color / _TrueColor isolate the
+// libghostty-vt CGO cost — same frames the Pipeline benchmarks use,
+// but feeding only the emulator. The delta between this and
+// BenchmarkASCIIVideo_Stream_… is the renderer's share; the rest
+// is libghostty-vt.
+func BenchmarkEmulator_Write_8Color_Frame(b *testing.B) {
+	frame := buildASCIIVideoFrame(80, 40)
+	b.SetBytes(int64(len(frame)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		em, err := vt.NewGhosttyEmulator(80, 40)
+		if err != nil {
+			b.Fatalf("emulator: %v", err)
+		}
+		if _, werr := em.Write(frame); werr != nil {
+			b.Fatalf("emulator.Write: %v", werr)
+		}
+		_ = em.Close()
+	}
+}
+
+func BenchmarkEmulator_Write_TrueColor_Frame(b *testing.B) {
+	frame := buildASCIIVideoFrameTrueColor(80, 40)
+	b.SetBytes(int64(len(frame)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		em, err := vt.NewGhosttyEmulator(80, 40)
+		if err != nil {
+			b.Fatalf("emulator: %v", err)
+		}
+		if _, werr := em.Write(frame); werr != nil {
+			b.Fatalf("emulator.Write: %v", werr)
+		}
+		_ = em.Close()
+	}
+}
+
+// BenchmarkEmulator_Write_Stream_120fps reuses one emulator across
+// 360 frames (3 sec × 120 fps). This is the cleanest measurement
+// of em.Write steady-state cost.
+func BenchmarkEmulator_Write_Stream_8Color_120fps(b *testing.B) {
+	frame := buildASCIIVideoFrame(80, 40)
+	const frames = 360
+	b.SetBytes(int64(len(frame) * frames))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		em, err := vt.NewGhosttyEmulator(80, 40)
+		if err != nil {
+			b.Fatalf("emulator: %v", err)
+		}
+		for f := 0; f < frames; f++ {
+			if _, werr := em.Write(frame); werr != nil {
+				b.Fatalf("emulator.Write: %v", werr)
+			}
+		}
+		_ = em.Close()
+	}
+	nsPerFrame := float64(b.Elapsed().Nanoseconds()) / float64(b.N*frames)
+	b.ReportMetric(nsPerFrame/1000.0, "µs/frame")
+	b.ReportMetric(1e9/nsPerFrame, "fps_ceiling")
+}
+
+func BenchmarkEmulator_Write_Stream_TrueColor_120fps(b *testing.B) {
+	frame := buildASCIIVideoFrameTrueColor(80, 40)
+	const frames = 360
+	b.SetBytes(int64(len(frame) * frames))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		em, err := vt.NewGhosttyEmulator(80, 40)
+		if err != nil {
+			b.Fatalf("emulator: %v", err)
+		}
+		for f := 0; f < frames; f++ {
+			if _, werr := em.Write(frame); werr != nil {
+				b.Fatalf("emulator.Write: %v", werr)
+			}
+		}
+		_ = em.Close()
+	}
+	nsPerFrame := float64(b.Elapsed().Nanoseconds()) / float64(b.N*frames)
+	b.ReportMetric(nsPerFrame/1000.0, "µs/frame")
+	b.ReportMetric(1e9/nsPerFrame, "fps_ceiling")
+}
+
+// runPipelineStreamBench includes the libghostty-vt emulator.Write
+// CGO call and a stdout write to io.Discard alongside the renderer
+// — i.e. everything OnPTYOut does in production except the host
+// terminal's own paint time (which patterm doesn't control). This
+// is the honest "can we hit N fps end-to-end?" measurement.
+func runPipelineStreamBench(b *testing.B, frame []byte, fps int) {
+	frames := fps * 3
+	totalBytes := int64(len(frame) * frames)
+	b.SetBytes(totalBytes)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		em, err := vt.NewGhosttyEmulator(80, 40)
+		if err != nil {
+			b.Fatalf("emulator: %v", err)
+		}
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		for f := 0; f < frames; f++ {
+			if _, werr := em.Write(frame); werr != nil {
+				b.Fatalf("emulator.Write: %v", werr)
+			}
+			out := vr.Render(frame)
+			// Match OnPTYOut's autowrap prelude/postlude wrapping so
+			// the byte count is faithful.
+			_, _ = io.Discard.Write([]byte("\x1b[?7l"))
+			_, _ = io.Discard.Write(out)
+			_, _ = io.Discard.Write([]byte("\x1b[?7h"))
+		}
+		_ = em.Close()
+	}
+	nsPerFrame := float64(b.Elapsed().Nanoseconds()) / float64(b.N*frames)
+	b.ReportMetric(nsPerFrame/1000.0, "µs/frame")
+	b.ReportMetric(1e9/nsPerFrame, "fps_ceiling")
+	budgetNs := 1e9 / float64(fps)
+	b.ReportMetric(nsPerFrame/budgetNs*100, "budget_pct")
+}
+
+// BenchmarkPipeline_ASCIIVideo_* — the FULL OnPTYOut path
+// (emulator.Write CGO + viewport renderer + a stdout write to
+// io.Discard) running at 30/60/120 fps targets. These are the
+// numbers to trust when asking "can we sustain N fps?" The
+// renderer-only Stream benchmarks above isolate one stage and
+// understate the real cost.
+//
+// 120 fps is the explicit baseline: anything under 100% of the
+// per-frame budget here means we hit 120 fps with margin to spare.
+func BenchmarkPipeline_ASCIIVideo_8Color_30fps(b *testing.B) {
+	runPipelineStreamBench(b, buildASCIIVideoFrame(80, 40), 30)
+}
+func BenchmarkPipeline_ASCIIVideo_8Color_60fps(b *testing.B) {
+	runPipelineStreamBench(b, buildASCIIVideoFrame(80, 40), 60)
+}
+func BenchmarkPipeline_ASCIIVideo_8Color_120fps(b *testing.B) {
+	runPipelineStreamBench(b, buildASCIIVideoFrame(80, 40), 120)
+}
+
+func BenchmarkPipeline_ASCIIVideo_TrueColor_30fps(b *testing.B) {
+	runPipelineStreamBench(b, buildASCIIVideoFrameTrueColor(80, 40), 30)
+}
+func BenchmarkPipeline_ASCIIVideo_TrueColor_60fps(b *testing.B) {
+	runPipelineStreamBench(b, buildASCIIVideoFrameTrueColor(80, 40), 60)
+}
+func BenchmarkPipeline_ASCIIVideo_TrueColor_120fps(b *testing.B) {
+	runPipelineStreamBench(b, buildASCIIVideoFrameTrueColor(80, 40), 120)
+}
+
+// BenchmarkSessionResume_5MiBStyled simulates the user's
+// motivating case: claude resuming a long chat session and dumping
+// the whole history. 5 MiB of styled output as a single Render
+// call. Numbers here tell us how long the visible "scrolling
+// while resume loads" window will be.
+func BenchmarkSessionResume_5MiBStyled(b *testing.B) {
+	chunk := buildStyledLinesChunk(5 * 1024 * 1024)
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(chunk)
+	}
+}
+
+// BenchmarkSessionResume_5MiBPlain same as above but pure text.
+// Lower bound — what we'd hit if the resume content were styling-
+// free.
+func BenchmarkSessionResume_5MiBPlain(b *testing.B) {
+	chunk := buildPlainASCIIChunk(5 * 1024 * 1024)
+	b.SetBytes(int64(len(chunk)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		vr := newViewportRenderer(newTerminalLayout(120, 40))
+		_ = vr.Render(chunk)
+	}
+}

internal/app/canonical.go

@@ -0,0 +1,143 @@
+package app
+
+import (
+	"regexp"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+var (
+	statusVolatileRE = regexp.MustCompile(`\b(?:\d+h\s*)?\d+m\s*\d+s\b|\b\d{1,2}:\d{2}(?::\d{2})?\b|\b\d+(?:\.\d+)?s\b`)
+	counterRE        = regexp.MustCompile(`\b\d+\s*/\s*\d+\b|\b\d{1,3}%`)
+	spinnerGlyphRE   = regexp.MustCompile(`^[\s⠁⠂⠄⡀⢀⠠⠐⠈⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏•·∙◐◓◑◒]+`)
+)
+
+func canonicalizeTerminalText(s string, maxLines int) (string, bool, int) {
+	s = string(stripANSIBytes(nil, []byte(s)))
+	s = strings.ReplaceAll(s, "\r\n", "\n")
+	s = carriageReturnToLines(s)
+	s = strings.ReplaceAll(s, "\r", "\n")
+
+	lines := strings.Split(s, "\n")
+	out := make([]string, 0, len(lines))
+	pendingBlank := false
+	for _, raw := range lines {
+		line := strings.TrimRightFunc(stripControlRunes(raw), unicode.IsSpace)
+		if strings.TrimSpace(line) == "" {
+			if len(out) > 0 {
+				pendingBlank = true
+			}
+			continue
+		}
+		if isBorderOnlyLine(line) {
+			continue
+		}
+		line = canonicalStatusLine(line)
+		if len(out) > 0 && out[len(out)-1] == line {
+			pendingBlank = false
+			continue
+		}
+		if pendingBlank {
+			out = append(out, "")
+			pendingBlank = false
+		}
+		out = append(out, line)
+	}
+
+	if maxLines > 0 && len(out) > maxLines {
+		dropped := strings.Join(out[:len(out)-maxLines], "\n")
+		out = out[len(out)-maxLines:]
+		return strings.Join(out, "\n"), true, len(dropped)
+	}
+	return strings.Join(out, "\n"), false, 0
+}
+
+func carriageReturnToLines(s string) string {
+	var out []string
+	var current strings.Builder
+	flush := func() {
+		out = append(out, current.String())
+		current.Reset()
+	}
+	for len(s) > 0 {
+		r, size := utf8.DecodeRuneInString(s)
+		s = s[size:]
+		switch r {
+		case '\r':
+			current.Reset()
+		case '\n':
+			flush()
+		default:
+			current.WriteRune(r)
+		}
+	}
+	if current.Len() > 0 || len(out) == 0 {
+		flush()
+	}
+	return strings.Join(out, "\n")
+}
+
+func stripControlRunes(s string) string {
+	return strings.Map(func(r rune) rune {
+		if r == '\t' || r == '\n' {
+			return r
+		}
+		if unicode.IsControl(r) {
+			return -1
+		}
+		return r
+	}, s)
+}
+
+func isBorderOnlyLine(s string) bool {
+	trimmed := strings.TrimSpace(s)
+	if trimmed == "" {
+		return false
+	}
+	seenBox := false
+	for _, r := range trimmed {
+		if r >= 0x2500 && r <= 0x257f {
+			seenBox = true
+			continue
+		}
+		switch r {
+		case ' ', '\t', '-', '_', '=', '+', '|', ':', '.', '\'', '"', '`', '*':
+			continue
+		default:
+			return false
+		}
+	}
+	return seenBox
+}
+
+func canonicalStatusLine(s string) string {
+	if !looksStatusLike(s) {
+		return s
+	}
+	leading := len(s) - len(strings.TrimLeftFunc(s, unicode.IsSpace))
+	prefix := s[:leading]
+	body := s[leading:]
+	body = spinnerGlyphRE.ReplaceAllString(body, "")
+	body = statusVolatileRE.ReplaceAllString(body, "[time]")
+	body = counterRE.ReplaceAllString(body, "[count]")
+	return prefix + strings.TrimRightFunc(body, unicode.IsSpace)
+}
+
+func looksStatusLike(s string) bool {
+	lower := strings.ToLower(s)
+	for _, token := range []string{
+		"status", "running", "remaining", "progress", "loading",
+		"building", "installing", "downloading", "waiting", "working",
+	} {
+		if strings.Contains(lower, token) {
+			return true
+		}
+	}
+	trimmed := strings.TrimSpace(s)
+	if trimmed == "" {
+		return false
+	}
+	r, _ := utf8.DecodeRuneInString(trimmed)
+	return strings.ContainsRune("⠁⠂⠄⡀⢀⠠⠐⠈⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏•·∙◐◓◑◒", r)
+}

internal/app/canonical_test.go

@@ -0,0 +1,167 @@
+package app
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/hjbdev/patterm/internal/mcp"
+	"github.com/hjbdev/patterm/internal/preset"
+)
+
+func TestCanonicalizeTerminalText(t *testing.T) {
+	cases := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "ansi osc and controls",
+			in:   "\x1b]0;title\x07\x1b[31mred\x1b[0m\x00\nok",
+			want: "red\nok",
+		},
+		{
+			name: "noisy harness stream",
+			in:   "\x1b]0;noise\x07\x1b[31mStatus: running 12s\x1b[0m\nStatus: running 13s\n╭────╮\n│    │\nDownloading 10%\rDownloading 100%\nFINAL: deploy ready\n",
+			want: "Status: running [time]\nDownloading [count]\nFINAL: deploy ready",
+		},
+		{
+			name: "repeated blank collapse",
+			in:   "one\n\n\n two\n \n\t\nthree",
+			want: "one\n\n two\n\nthree",
+		},
+		{
+			name: "border only box drawing removal",
+			in:   "╭────────╮\n│        │\nimportant\n╰────────╯",
+			want: "important",
+		},
+		{
+			name: "carriage return progress coalesces final frame",
+			in:   "Downloading 10%\rDownloading 20%\rDownloading 100%\nDone",
+			want: "Downloading [count]\nDone",
+		},
+		{
+			name: "volatile timer duplicate collapse",
+			in:   "Status: running 12s\nStatus: running 13s\nStatus: running 01:23",
+			want: "Status: running [time]",
+		},
+		{
+			name: "duplicate status row collapse",
+			in:   "⠋ Building 1/4\n⠙ Building 2/4\n⠹ Building 3/4\nready",
+			want: "Building [count]\nready",
+		},
+		{
+			name: "preserve meaningful indented code and tables",
+			in:   "  if elapsed == 12s {\n    return value\n  }\n| name | value |\n| a    | 1     |",
+			want: "  if elapsed == 12s {\n    return value\n  }\n| name | value |\n| a    | 1     |",
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, truncated, _ := canonicalizeTerminalText(tc.in, 120)
+			if truncated {
+				t.Fatalf("unexpected truncation")
+			}
+			if got != tc.want {
+				t.Fatalf("got %q want %q", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestCanonicalizeTerminalTextMaxLines(t *testing.T) {
+	got, truncated, dropped := canonicalizeTerminalText("one\ntwo\nthree", 2)
+	if !truncated {
+		t.Fatalf("expected truncation")
+	}
+	if dropped == 0 {
+		t.Fatalf("expected dropped bytes")
+	}
+	if got != "two\nthree" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestGetProcessOutputStreamCanonicalByDefault(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	c := newChildEntry("p1", "proc", KindCommand, nil, nil, "", "", "")
+	addChild(sess, c)
+	c.recordWrite([]byte("\x1b[31mStatus: running 12s\x1b[0m\nStatus: running 13s\nresult\n"))
+	host := newToolHost(sess, nil, nil, preset.Set{}, nil, 80, 24)
+
+	out, err := host.GetProcessOutput("", mcp.ProcessOutputArgs{ProcessID: c.ID, Mode: "stream"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !out.Canonicalized {
+		t.Fatalf("expected canonicalized output")
+	}
+	if out.Content != "Status: running [time]\nresult" {
+		t.Fatalf("content = %q", out.Content)
+	}
+	if out.Cursor != nil || out.Rows != 0 || out.Cols != 0 || out.ScreenVersion != 0 || out.IdleMS != 0 {
+		t.Fatalf("default output should be metadata-light: %#v", out)
+	}
+}
+
+func TestGetProcessOutputRawReturnsStreamBytes(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	c := newChildEntry("p1", "proc", KindCommand, nil, nil, "", "", "")
+	addChild(sess, c)
+	c.recordWrite([]byte("\x1b[31mred\x1b[0m"))
+	host := newToolHost(sess, nil, nil, preset.Set{}, nil, 80, 24)
+
+	out, err := host.GetProcessOutput("", mcp.ProcessOutputArgs{ProcessID: c.ID, Mode: "grid", Raw: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out.Mode != "stream" {
+		t.Fatalf("raw grid mode should report stream semantics, got %q", out.Mode)
+	}
+	if out.Canonicalized {
+		t.Fatalf("raw output should not be canonicalized")
+	}
+	if out.Content != "\x1b[31mred\x1b[0m" {
+		t.Fatalf("content = %q", out.Content)
+	}
+	if out.NewOffset != int64(len(out.Content)) {
+		t.Fatalf("new_offset=%d want %d", out.NewOffset, len(out.Content))
+	}
+}
+
+func TestGetProcessOutputCanonicalAfterRawRead(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	c := newChildEntry("p1", "proc", KindCommand, nil, nil, "", "", "")
+	addChild(sess, c)
+	c.recordWrite([]byte("\x1b[31mStatus: running 12s\x1b[0m\nStatus: running 13s\nDownloading 10%\rDownloading 100%\nFINAL: deploy ready\n"))
+	host := newToolHost(sess, nil, nil, preset.Set{}, nil, 80, 24)
+
+	if _, err := host.GetProcessOutput("", mcp.ProcessOutputArgs{ProcessID: c.ID, Mode: "stream", Raw: true}); err != nil {
+		t.Fatal(err)
+	}
+	out, err := host.GetProcessOutput("", mcp.ProcessOutputArgs{ProcessID: c.ID, Mode: "stream", MaxLines: 20})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out.Content != "Status: running [time]\nDownloading [count]\nFINAL: deploy ready" {
+		t.Fatalf("content = %q", out.Content)
+	}
+}
+
+func TestGetProcessOutputIncludeMetaRestoresFields(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	c := newChildEntry("p1", "proc", KindCommand, nil, nil, "", "", "")
+	addChild(sess, c)
+	c.recordWrite([]byte("ok"))
+	host := newToolHost(sess, nil, nil, preset.Set{}, nil, 80, 24)
+
+	out, err := host.GetProcessOutput("", mcp.ProcessOutputArgs{ProcessID: c.ID, Mode: "stream", IncludeMeta: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out.ScreenVersion == 0 {
+		t.Fatalf("screen_version missing with include_meta: %#v", out)
+	}
+	if !strings.Contains(out.Content, "ok") {
+		t.Fatalf("content = %q", out.Content)
+	}
+}

internal/app/child.go

@@ -26,6 +26,11 @@ import (
 // false positives (timestamps, exit codes, etc.).
 var portRegex = regexp.MustCompile(`https?://[^\s:/]+:(\d{2,5})(?:/[^\s]*)?`)
 
+const (
+	agentInterPieceDelay   = 15 * time.Millisecond
+	agentSubmitSettleDelay = 100 * time.Millisecond
+)
+
 type ChildStatus string
 
 const (
@@ -527,6 +532,12 @@ func (c *Child) StreamRead(since int64) ([]byte, int64) {
 	return out, end
 }
 
+func (c *Child) StreamOffset() int64 {
+	c.ringMu.Lock()
+	defer c.ringMu.Unlock()
+	return c.ringWrites
+}
+
 func (c *Child) signal(sig syscall.Signal) error {
 	pty := c.PTY()
 	if pty == nil {
@@ -625,25 +636,25 @@ func (c *Child) InjectAsOrchestrator(b []byte) error {
 }
 
 // writeInput is the shared PTY write path used by both injection
-// flavours. Each Enter byte (CR or LF) is split onto its own write
-// with a brief delay so TUI agents with paste-detection (claude,
+// flavours. Agent panes split each Enter byte (CR or LF) onto its own
+// write with a brief delay so TUI agents with paste-detection (claude,
 // codex, opencode) don't coalesce a trailing CR into the text that
-// preceded it. Without the split, `pty.Write([]byte("hello\r"))`
-// arrives at the agent as one read() and gets treated as multi-line
-// pasted content rather than "key Enter".
+// preceded it. Raw terminals and command panes receive the original
+// byte stream in one write; otherwise a multiline paste pays the agent
+// workaround's delay once per line.
 func (c *Child) writeInput(b []byte) error {
 	pty := c.PTY()
 	if pty == nil {
 		return errors.New("child has no pty")
 	}
-	pieces := splitOnEnter(b)
+	pieces := inputWritePieces(c.Kind, b)
 	if len(pieces) <= 1 {
 		_, err := pty.Write(b)
 		return err
 	}
 	for i, piece := range pieces {
-		if i > 0 {
-			time.Sleep(15 * time.Millisecond)
+		if delay := pieceWriteDelay(i, len(pieces), piece); delay > 0 {
+			time.Sleep(delay)
 		}
 		if _, err := pty.Write(piece); err != nil {
 			return err
@@ -652,6 +663,27 @@ func (c *Child) writeInput(b []byte) error {
 	return nil
 }
 
+func inputWritePieces(kind ChildKind, b []byte) [][]byte {
+	if kind != KindAgent {
+		return [][]byte{b}
+	}
+	return splitOnEnter(b)
+}
+
+func pieceWriteDelay(index, total int, piece []byte) time.Duration {
+	if index == 0 {
+		return 0
+	}
+	if index == total-1 && isLoneEnter(piece) {
+		return agentSubmitSettleDelay
+	}
+	return agentInterPieceDelay
+}
+
+func isLoneEnter(piece []byte) bool {
+	return len(piece) == 1 && (piece[0] == '\r' || piece[0] == '\n')
+}
+
 func mintIdentity() string {
 	var buf [12]byte
 	_, _ = rand.Read(buf[:])

internal/app/child_input_test.go

@@ -0,0 +1,90 @@
+package app
+
+import (
+	"bytes"
+	"testing"
+	"time"
+)
+
+func TestInputWritePiecesOnlySplitAgentEnters(t *testing.T) {
+	in := []byte("alpha\nbeta\rgamma")
+	for _, kind := range []ChildKind{KindTerminal, KindCommand} {
+		t.Run(string(kind), func(t *testing.T) {
+			got := inputWritePieces(kind, in)
+			if len(got) != 1 || !bytes.Equal(got[0], in) {
+				t.Fatalf("inputWritePieces(%s) = %#v, want one original chunk", kind, got)
+			}
+		})
+	}
+
+	got := inputWritePieces(KindAgent, in)
+	if len(got) != 5 {
+		t.Fatalf("agent pieces len = %d, want 5 (%#v)", len(got), got)
+	}
+	want := [][]byte{[]byte("alpha"), []byte("\n"), []byte("beta"), []byte("\r"), []byte("gamma")}
+	for i := range want {
+		if !bytes.Equal(got[i], want[i]) {
+			t.Fatalf("agent piece %d = %q, want %q", i, got[i], want[i])
+		}
+	}
+}
+
+func TestPieceWriteDelay(t *testing.T) {
+	cases := []struct {
+		name  string
+		index int
+		total int
+		piece []byte
+		want  time.Duration
+	}{
+		{
+			name:  "first piece",
+			index: 0,
+			total: 3,
+			piece: []byte("body"),
+			want:  0,
+		},
+		{
+			name:  "middle body piece",
+			index: 1,
+			total: 3,
+			piece: []byte("body"),
+			want:  agentInterPieceDelay,
+		},
+		{
+			name:  "final carriage return submit",
+			index: 1,
+			total: 2,
+			piece: []byte("\r"),
+			want:  agentSubmitSettleDelay,
+		},
+		{
+			name:  "final newline submit",
+			index: 1,
+			total: 2,
+			piece: []byte("\n"),
+			want:  agentSubmitSettleDelay,
+		},
+		{
+			name:  "final non-enter piece",
+			index: 2,
+			total: 3,
+			piece: []byte("tail"),
+			want:  agentInterPieceDelay,
+		},
+		{
+			name:  "standalone enter fast path",
+			index: 0,
+			total: 1,
+			piece: []byte("\r"),
+			want:  0,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := pieceWriteDelay(tc.index, tc.total, tc.piece); got != tc.want {
+				t.Fatalf("pieceWriteDelay(%d, %d, %q) = %s, want %s", tc.index, tc.total, tc.piece, got, tc.want)
+			}
+		})
+	}
+}

internal/app/classifier.go

@@ -50,8 +50,14 @@ func (s *Session) classifyOne(c *Child) {
 	idleMS := c.IdleMS()
 	titleIdleMS := c.TitleIdleMS()
 	title := c.Title()
-	tail := c.tailBytes(classifierTailBytes)
-	state, reason := classify(c.idleDetection, exited, exitNonZero, idleMS, titleIdleMS, title, tail)
+	tail := stripANSIBytes(nil, c.tailBytes(classifierTailBytes))
+	var screen []byte
+	if em := c.Emulator(); em != nil {
+		if txt, err := em.ScreenText(); err == nil {
+			screen = []byte(txt)
+		}
+	}
+	state, reason := classify(c.idleDetection, exited, exitNonZero, idleMS, titleIdleMS, title, tail, screen)
 	if c.setIdleState(state, reason) {
 		s.emitStateChanged(c.ID, state)
 	}

internal/app/debug.go

@@ -0,0 +1,162 @@
+package app
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+// debugCapture implements ChildEventListener and writes structured
+// debug artefacts under a single directory:
+//
+//   - patterm.log    — the existing logf() stream
+//   - events.jsonl   — one JSON object per lifecycle event
+//   - <id>.raw       — raw PTY bytes for each child, by id+name
+//
+// The capture is installed only when --debug=<dir> is set, so default
+// runs pay nothing.
+type debugCapture struct {
+	dir     string
+	logPath string
+
+	mu      sync.Mutex
+	events  *os.File
+	rawByID map[string]*os.File
+}
+
+func openDebugCapture(dir string) (*debugCapture, error) {
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return nil, err
+	}
+	logPath := filepath.Join(dir, "patterm.log")
+	// Truncate-style fresh log per run is friendlier for grep'ing one
+	// session. The existing logf opens O_APPEND though, so concurrent
+	// runs against the same dir would interleave — that's on the user.
+	if f, err := os.Create(logPath); err != nil {
+		return nil, err
+	} else {
+		_ = f.Close()
+	}
+	ev, err := os.Create(filepath.Join(dir, "events.jsonl"))
+	if err != nil {
+		return nil, err
+	}
+	dc := &debugCapture{
+		dir:     dir,
+		logPath: logPath,
+		events:  ev,
+		rawByID: make(map[string]*os.File),
+	}
+	dc.writeEvent("session_start", map[string]any{
+		"time": time.Now().Format(time.RFC3339Nano),
+		"pid":  os.Getpid(),
+	})
+	return dc, nil
+}
+
+func (d *debugCapture) LogPath() string { return d.logPath }
+
+func (d *debugCapture) Close() error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	d.writeEventLocked("session_end", map[string]any{
+		"time": time.Now().Format(time.RFC3339Nano),
+	})
+	for _, f := range d.rawByID {
+		_ = f.Close()
+	}
+	d.rawByID = nil
+	if d.events != nil {
+		_ = d.events.Close()
+		d.events = nil
+	}
+	return nil
+}
+
+func (d *debugCapture) OnChildSpawned(c *Child) {
+	d.writeEvent("child_spawned", map[string]any{
+		"time":      time.Now().Format(time.RFC3339Nano),
+		"id":        c.ID,
+		"name":      c.Name,
+		"kind":      string(c.Kind),
+		"parent_id": c.ParentID,
+		"preset":    c.PresetRef,
+		"argv":      c.Argv,
+	})
+}
+
+func (d *debugCapture) OnChildExited(c *Child) {
+	d.writeEvent("child_exited", map[string]any{
+		"time":      time.Now().Format(time.RFC3339Nano),
+		"id":        c.ID,
+		"name":      c.Name,
+		"exit_code": c.ExitCode(),
+	})
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if f, ok := d.rawByID[c.ID]; ok {
+		_ = f.Close()
+		delete(d.rawByID, c.ID)
+	}
+}
+
+func (d *debugCapture) OnChildStateChanged(id string, state IdleState) {
+	d.writeEvent("child_state", map[string]any{
+		"time":  time.Now().Format(time.RFC3339Nano),
+		"id":    id,
+		"state": string(state),
+	})
+}
+
+func (d *debugCapture) OnChildClosed(id string) {
+	d.writeEvent("child_closed", map[string]any{
+		"time": time.Now().Format(time.RFC3339Nano),
+		"id":   id,
+	})
+}
+
+func (d *debugCapture) OnPTYOut(childID string, chunk []byte) {
+	if len(chunk) == 0 {
+		return
+	}
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	f, ok := d.rawByID[childID]
+	if !ok {
+		path := filepath.Join(d.dir, childID+".raw")
+		nf, err := os.Create(path)
+		if err != nil {
+			return
+		}
+		f = nf
+		d.rawByID[childID] = nf
+	}
+	// Listener contract: don't retain chunk past return. Writing now
+	// is fine; the slice's backing buffer is reused for the next read
+	// only after this listener chain completes.
+	_, _ = f.Write(chunk)
+}
+
+func (d *debugCapture) writeEvent(kind string, fields map[string]any) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	d.writeEventLocked(kind, fields)
+}
+
+func (d *debugCapture) writeEventLocked(kind string, fields map[string]any) {
+	if d.events == nil {
+		return
+	}
+	if fields == nil {
+		fields = map[string]any{}
+	}
+	fields["event"] = kind
+	enc, err := json.Marshal(fields)
+	if err != nil {
+		return
+	}
+	_, _ = fmt.Fprintln(d.events, string(enc))
+}

internal/app/host.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"syscall"
 	"time"
+	"unicode"
 
 	"github.com/hjbdev/patterm/internal/mcp"
 	"github.com/hjbdev/patterm/internal/preset"
@@ -64,6 +65,17 @@ type toolHost struct {
 	timers *timerManager
 }
 
+const (
+	defaultMCPContentBytes     = 12_000
+	maxMCPContentBytes         = 65_536
+	defaultMCPCanonicalLines   = 120
+	maxMCPCanonicalLines       = 500
+	defaultMCPTailBytes        = 8_000
+	defaultScratchpadReadBytes = 12_000
+	defaultSearchLineBytes     = 2_000
+	maxSearchMatches           = 50
+)
+
 func newToolHost(sess *Session, pads *scratchpad.Store, launcher *Launcher, presets preset.Set, tr *trust.Store, cols, rows uint16) *toolHost {
 	h := &toolHost{
 		sess:       sess,
@@ -86,10 +98,10 @@ func newToolHost(sess *Session, pads *scratchpad.Store, launcher *Launcher, pres
 	return h
 }
 
-// timerListenerAdapter forwards OnChildStateChanged into the timer
-// manager and ignores the other ChildEventListener methods. The
-// session's listener API is by-interface, so we wrap the manager
-// rather than make it implement the full surface.
+// timerListenerAdapter forwards OnChildStateChanged and OnChildClosed
+// into the timer manager and ignores the other ChildEventListener
+// methods. The session's listener API is by-interface, so we wrap
+// the manager rather than make it implement the full surface.
 type timerListenerAdapter struct{ m *timerManager }
 
 func (a timerListenerAdapter) OnChildSpawned(*Child)   {}
@@ -98,6 +110,9 @@ func (a timerListenerAdapter) OnPTYOut(string, []byte) {}
 func (a timerListenerAdapter) OnChildStateChanged(id string, st IdleState) {
 	a.m.onChildStateChanged(id, st)
 }
+func (a timerListenerAdapter) OnChildClosed(id string) {
+	a.m.onChildClosed(id)
+}
 
 func (h *toolHost) SetSize(cols, rows uint16) {
 	h.sizeMu.Lock()
@@ -349,8 +364,8 @@ func (h *toolHost) GetProcessStatus(callerID, processID string) (mcp.ProcessStat
 	return st, nil
 }
 
-func (h *toolHost) GetProjectStatus(callerID string) (mcp.ProjectStatus, error) {
-	caller := h.WhoAmI(callerID)
+func (h *toolHost) GetProjectStatus(callerID string, includeTools bool) (mcp.ProjectStatus, error) {
+	caller := h.WhoAmI(callerID, includeTools)
 	processes := h.ListProcesses(callerID, "")
 	pads, _ := h.pads.List()
 	return mcp.ProjectStatus{
@@ -361,27 +376,48 @@ func (h *toolHost) GetProjectStatus(callerID string) (mcp.ProjectStatus, error)
 	}, nil
 }
 
-func (h *toolHost) GetProcessOutput(callerID, processID, mode string, sinceOffset int64) (mcp.ProcessOutput, error) {
+func (h *toolHost) GetProcessOutput(callerID string, args mcp.ProcessOutputArgs) (mcp.ProcessOutput, error) {
+	processID, mode, sinceOffset := args.ProcessID, args.Mode, args.SinceOffset
 	c := h.sess.FindChild(processID)
 	if c == nil {
 		return mcp.ProcessOutput{}, mcp.Errorf(mcp.ErrorKindNotFound, "no such process %q", processID)
 	}
+	if mode == "" {
+		mode = "grid"
+	}
+	if args.Raw {
+		b, end := c.StreamRead(sinceOffset)
+		content, contentBytes, truncated, truncatedBytes := capBytesTail(b, capLimit(args.MaxBytes, defaultMCPContentBytes))
+		return mcp.ProcessOutput{
+			Content:        content,
+			Mode:           "stream",
+			NewOffset:      end,
+			Status:         string(c.Status()),
+			ContentBytes:   contentBytes,
+			Truncated:      truncated,
+			TruncatedBytes: truncatedBytes,
+		}, nil
+	}
 	out := mcp.ProcessOutput{
 		Mode:          mode,
-		IdleMS:        c.IdleMS(),
 		Status:        string(c.Status()),
-		ScreenVersion: c.ScreenVersion(),
+		Canonicalized: true,
 	}
-	if em := c.Emulator(); em != nil {
-		if sc, err := em.ActiveScreen(); err == nil {
-			out.ActiveScreen = activeScreenName(sc)
+	if args.IncludeMeta {
+		out.IdleMS = c.IdleMS()
+		out.ScreenVersion = c.ScreenVersion()
+		if em := c.Emulator(); em != nil {
+			if sc, err := em.ActiveScreen(); err == nil {
+				out.ActiveScreen = activeScreenName(sc)
+			}
+			if cur, err := em.Cursor(); err == nil {
+				out.Cursor = &mcp.Cursor{X: int(cur.Col), Y: int(cur.Row)}
+			}
+			cols, rows := em.Size()
+			out.Cols, out.Rows = int(cols), int(rows)
 		}
-		if cur, err := em.Cursor(); err == nil {
-			out.Cursor = mcp.Cursor{X: int(cur.Col), Y: int(cur.Row)}
-		}
-		cols, rows := em.Size()
-		out.Cols, out.Rows = int(cols), int(rows)
 	}
+	maxLines := canonicalLineLimit(args.MaxLines)
 	switch mode {
 	case "grid":
 		em := c.Emulator()
@@ -395,11 +431,21 @@ func (h *toolHost) GetProcessOutput(callerID, processID, mode string, sinceOffse
 		if c.Kind == KindAgent {
 			txt = applyChromeTrim(txt, h.chromeHintsFor(c.PresetRef))
 		}
-		out.Content = txt
+		content, lineTruncated, lineDroppedBytes := canonicalizeTerminalText(txt, maxLines)
+		out.Content, out.ContentBytes, out.Truncated, out.TruncatedBytes = capTextMiddle(content, capLimit(args.MaxBytes, defaultMCPContentBytes))
+		if lineTruncated {
+			out.Truncated = true
+			out.TruncatedBytes += lineDroppedBytes
+		}
 		return out, nil
 	case "stream":
 		b, end := c.StreamRead(sinceOffset)
-		out.Content = string(stripANSIBytes(nil, b))
+		content, lineTruncated, lineDroppedBytes := canonicalizeTerminalText(string(b), maxLines)
+		out.Content, out.ContentBytes, out.Truncated, out.TruncatedBytes = capTextTail(content, capLimit(args.MaxBytes, defaultMCPContentBytes))
+		if lineTruncated {
+			out.Truncated = true
+			out.TruncatedBytes += lineDroppedBytes
+		}
 		out.NewOffset = end
 		return out, nil
 	default:
@@ -407,34 +453,46 @@ func (h *toolHost) GetProcessOutput(callerID, processID, mode string, sinceOffse
 	}
 }
 
-func (h *toolHost) GetProcessRawOutput(callerID, processID string, sinceOffset int64) (mcp.RawOutput, error) {
-	c := h.sess.FindChild(processID)
+func (h *toolHost) GetProcessRawOutput(callerID string, args mcp.RawOutputArgs) (mcp.RawOutput, error) {
+	c := h.sess.FindChild(args.ProcessID)
 	if c == nil {
-		return mcp.RawOutput{}, mcp.Errorf(mcp.ErrorKindNotFound, "no such process %q", processID)
+		return mcp.RawOutput{}, mcp.Errorf(mcp.ErrorKindNotFound, "no such process %q", args.ProcessID)
 	}
-	b, end := c.StreamRead(sinceOffset)
+	b, end := c.StreamRead(args.SinceOffset)
+	content, contentBytes, truncated, truncatedBytes := capBytesTail(b, capLimit(args.MaxBytes, defaultMCPContentBytes))
 	return mcp.RawOutput{
-		Content:   string(b),
-		NewOffset: end,
-		Status:    string(c.Status()),
+		Content:        content,
+		NewOffset:      end,
+		Status:         string(c.Status()),
+		ContentBytes:   contentBytes,
+		Truncated:      truncated,
+		TruncatedBytes: truncatedBytes,
 	}, nil
 }
 
-func (h *toolHost) SearchOutput(callerID, processID, pattern, kind string, limit int) (mcp.SearchResult, error) {
-	c := h.sess.FindChild(processID)
+func (h *toolHost) SearchOutput(callerID string, args mcp.SearchOutputArgs) (mcp.SearchResult, error) {
+	c := h.sess.FindChild(args.ProcessID)
 	if c == nil {
-		return mcp.SearchResult{}, mcp.Errorf(mcp.ErrorKindNotFound, "no such process %q", processID)
+		return mcp.SearchResult{}, mcp.Errorf(mcp.ErrorKindNotFound, "no such process %q", args.ProcessID)
 	}
-	re, err := regexp.Compile(pattern)
+	re, err := regexp.Compile(args.Pattern)
 	if err != nil {
 		return mcp.SearchResult{}, mcp.Errorf(mcp.ErrorKindInvalidArgs, "regex: %v", err)
 	}
 	b, _ := c.StreamRead(0)
-	if kind == "rendered" {
+	if args.Kind == "rendered" {
 		b = stripANSIBytes(nil, b)
 	}
 	text := string(b)
 	lines := strings.Split(text, "\n")
+	limit := args.Limit
+	if limit <= 0 {
+		limit = 10
+	}
+	if limit > maxSearchMatches {
+		limit = maxSearchMatches
+	}
+	lineLimit := capLimit(args.MaxBytes, defaultSearchLineBytes)
 	matches := make([]mcp.SearchMatch, 0, limit)
 	truncated := false
 	for i, line := range lines {
@@ -443,6 +501,8 @@ func (h *toolHost) SearchOutput(callerID, processID, pattern, kind string, limit
 				truncated = true
 				break
 			}
+			line, _, lineTruncated, _ := capTextTail(line, lineLimit)
+			truncated = truncated || lineTruncated
 			matches = append(matches, mcp.SearchMatch{LineNo: i + 1, Text: line})
 		}
 	}
@@ -553,6 +613,7 @@ func (n *chunkNotifier) OnPTYOut(id string, chunk []byte) {
 	}
 }
 func (n *chunkNotifier) OnChildStateChanged(string, IdleState) {}
+func (n *chunkNotifier) OnChildClosed(string)                  {}
 
 func (h *toolHost) GetProcessPorts(callerID, processID string) ([]mcp.PortSighting, error) {
 	c := h.sess.FindChild(processID)
@@ -583,6 +644,7 @@ func (h *toolHost) SendInput(callerID string, args mcp.SendInputArgs) (mcp.SendI
 	if err != nil {
 		return mcp.SendInputResult{}, err
 	}
+	tailSince := c.StreamOffset()
 	if err := c.InjectAsOrchestrator(payload); err != nil {
 		return mcp.SendInputResult{}, err
 	}
@@ -594,7 +656,12 @@ func (h *toolHost) SendInput(callerID string, args mcp.SendInputArgs) (mcp.SendI
 		}
 		if mode != "none" {
 			time.Sleep(time.Duration(args.WaitMS) * time.Millisecond)
-			tail, err := h.GetProcessOutput(callerID, args.ProcessID, mode, 0)
+			tail, err := h.GetProcessOutput(callerID, mcp.ProcessOutputArgs{
+				ProcessID:   args.ProcessID,
+				Mode:        mode,
+				SinceOffset: tailSince,
+				MaxBytes:    capLimit(args.TailMaxBytes, defaultMCPTailBytes),
+			})
 			if err == nil {
 				res.Tail = &tail
 			}
@@ -808,8 +875,30 @@ func (h *toolHost) TimerList(callerID string) ([]mcp.TimerInfo, error) {
 
 func (h *toolHost) ScratchpadList() ([]scratchpad.Entry, error) { return h.pads.List() }
 
-func (h *toolHost) ScratchpadRead(name string) (string, string, error) {
-	return h.pads.Read(name)
+func (h *toolHost) ScratchpadRead(args mcp.ScratchpadReadArgs) (mcp.ScratchpadReadResult, error) {
+	content, rev, err := h.pads.Read(args.Name)
+	if err != nil {
+		return mcp.ScratchpadReadResult{}, err
+	}
+	offset := args.Offset
+	if offset < 0 {
+		offset = 0
+	}
+	if offset > len(content) {
+		offset = len(content)
+	}
+	limited, contentBytes, truncated, truncatedBytes := capTextHead(content[offset:], capLimit(args.MaxBytes, defaultScratchpadReadBytes))
+	next := offset + contentBytes
+	return mcp.ScratchpadReadResult{
+		Content:        limited,
+		Revision:       rev,
+		Offset:         offset,
+		NextOffset:     next,
+		ContentBytes:   contentBytes,
+		TotalBytes:     len(content),
+		Truncated:      truncated,
+		TruncatedBytes: truncatedBytes,
+	}, nil
 }
 
 func (h *toolHost) ScratchpadWrite(name, content, expectedRevision string) (string, error) {
@@ -828,7 +917,15 @@ func (h *toolHost) ScratchpadAppend(name, content string) error {
 	return err
 }
 
-func (h *toolHost) WhoAmI(callerID string) mcp.WhoAmI {
+func (h *toolHost) ScratchpadDelete(name string) error {
+	err := h.pads.Delete(name)
+	if err == nil && h.scratch != nil {
+		h.scratch.scratchpadsChanged()
+	}
+	return err
+}
+
+func (h *toolHost) WhoAmI(callerID string, includeTools bool) mcp.WhoAmI {
 	w := mcp.WhoAmI{
 		ProcessID: callerID,
 		Role:      h.CallerRole(callerID),
@@ -836,7 +933,9 @@ func (h *toolHost) WhoAmI(callerID string) mcp.WhoAmI {
 			Path: h.sess.projectDir,
 			Key:  h.sess.projectKey,
 		},
-		AvailableTools: availableToolsForRole(h.CallerRole(callerID)),
+	}
+	if includeTools {
+		w.AvailableTools = availableToolsForRole(h.CallerRole(callerID))
 	}
 	if c := h.sess.FindChild(callerID); c != nil {
 		w.Name = c.DisplayName()
@@ -996,22 +1095,101 @@ func activeScreenName(s pkgvt.Screen) string {
 	}
 }
 
-// ansiRegexp strips CSI escape sequences and common single-character
-// controls (BEL, OSC terminators) from the stream. The vt emulator
-// already handles full rendering for grid mode; this is only for
-// stream-mode ANSI-stripped output.
-var ansiRegexp = regexp.MustCompile(`\x1b\[[\x30-\x3f]*[\x20-\x2f]*[\x40-\x7e]|\x1b[\x40-\x5f]|\x07`)
+// ansiRegexp strips CSI/OSC escape sequences and common single-character
+// controls from the stream. The vt emulator already handles full
+// rendering for grid mode; this is only for stream-mode text output.
+var ansiRegexp = regexp.MustCompile(`\x1b\][^\x07\x1b]*(?:\x07|\x1b\\)|\x1b\[[\x30-\x3f]*[\x20-\x2f]*[\x40-\x7e]|\x1b[\x40-\x5f]|\x07`)
 
 func stripANSI(s string) string {
 	return ansiRegexp.ReplaceAllString(s, "")
 }
 
+func normalizeGridText(s string) string {
+	s = strings.ReplaceAll(s, "\r\n", "\n")
+	s = strings.ReplaceAll(s, "\r", "\n")
+
+	lines := strings.Split(s, "\n")
+	out := make([]string, 0, len(lines))
+	pendingBlank := false
+	for _, line := range lines {
+		line = strings.TrimRightFunc(line, unicode.IsSpace)
+		if line == "" {
+			if len(out) > 0 {
+				pendingBlank = true
+			}
+			continue
+		}
+		if pendingBlank {
+			out = append(out, "")
+			pendingBlank = false
+		}
+		out = append(out, line)
+	}
+	return strings.Join(out, "\n")
+}
+
+func capLimit(requested, def int) int {
+	if requested <= 0 {
+		requested = def
+	}
+	if requested > maxMCPContentBytes {
+		requested = maxMCPContentBytes
+	}
+	if requested < 0 {
+		return 0
+	}
+	return requested
+}
+
+func canonicalLineLimit(requested int) int {
+	if requested <= 0 {
+		return defaultMCPCanonicalLines
+	}
+	if requested > maxMCPCanonicalLines {
+		return maxMCPCanonicalLines
+	}
+	return requested
+}
+
+func capBytesTail(b []byte, limit int) (string, int, bool, int) {
+	if limit <= 0 || len(b) <= limit {
+		return string(b), len(b), false, 0
+	}
+	dropped := len(b) - limit
+	return string(b[dropped:]), limit, true, dropped
+}
+
+func capTextTail(s string, limit int) (string, int, bool, int) {
+	return capBytesTail([]byte(s), limit)
+}
+
+func capTextHead(s string, limit int) (string, int, bool, int) {
+	if limit <= 0 || len(s) <= limit {
+		return s, len(s), false, 0
+	}
+	return s[:limit], limit, true, len(s) - limit
+}
+
+func capTextMiddle(s string, limit int) (string, int, bool, int) {
+	if limit <= 0 || len(s) <= limit {
+		return s, len(s), false, 0
+	}
+	const marker = "\n...[truncated]...\n"
+	if limit <= len(marker)+2 {
+		return s[len(s)-limit:], limit, true, len(s) - limit
+	}
+	head := (limit - len(marker)) / 2
+	tail := limit - len(marker) - head
+	return s[:head] + marker + s[len(s)-tail:], limit, true, len(s) - limit
+}
+
 // stripANSIBytes is the byte-slice form of stripANSI. Skips the
 // string conversion and the regex DFA — useful when the caller will
 // itself walk the result line-by-line (SearchOutput) or feed it to a
 // pattern match (WaitForPattern scrollback). Recognises the same
 // shapes the regex did:
 //   - `\x1b[ <params> <intermediate> <final-byte>` (CSI / SGR)
+//   - `\x1b] ... (BEL|ST)` (OSC)
 //   - `\x1b<final-byte>` for `@..._` (one-byte escapes)
 //   - `\x07` (BEL)
 //
@@ -1041,6 +1219,24 @@ func stripANSIBytes(dst, src []byte) []byte {
 			continue
 		}
 		next := src[i+1]
+		if next == ']' {
+			j := i + 2
+			for j < len(src) {
+				if src[j] == 0x07 {
+					i = j + 1
+					break
+				}
+				if src[j] == 0x1b && j+1 < len(src) && src[j+1] == '\\' {
+					i = j + 2
+					break
+				}
+				j++
+			}
+			if j >= len(src) {
+				i = len(src)
+			}
+			continue
+		}
 		if next != '[' {
 			// One-byte ESC sequence (`\x1b<final>` where final is
 			// `@..._` per the regex; we drop anything that follows).
@@ -1087,7 +1283,7 @@ func availableToolsForRole(role mcp.CallerRole) []string {
 		"send_input", "send_message", "request_human_attention",
 		"timer_wait", "timer_set", "timer_fire_when_idle_any", "timer_fire_when_idle_all",
 		"timer_cancel", "timer_pause", "timer_resume", "timer_list",
-		"scratchpad_list", "scratchpad_read", "scratchpad_write", "scratchpad_append",
+		"scratchpad_list", "scratchpad_read", "scratchpad_write", "scratchpad_append", "scratchpad_delete",
 		"whoami", "help",
 	}
 	if role == mcp.RoleOrchestrator {
@@ -1111,7 +1307,7 @@ func helpFor(topic string) mcp.HelpResponse {
 	case "spawning":
 		return mcp.HelpResponse{
 			Topic:        "spawning",
-			Content:      "spawn_agent launches another vendor LLM CLI as a sub-agent (orchestrator only). spawn_process(kind: command, preset: …) starts a stored command; spawn_process(kind: terminal) opens a shell. Command presets need trust the first time — you'll get needs_trust until the human accepts. Whatever you spawn is yours to clean up — see help('lifecycle').",
+			Content:      "spawn_agent launches another vendor LLM CLI as a sub-agent (orchestrator only). spawn_process(kind: command, preset: …) starts a stored command; spawn_process(kind: terminal) opens a shell. Command presets need trust the first time — you'll get needs_trust until the human accepts. ANTI-PATTERNS: do not shell out to `claude` / `codex` / `opencode` (or any other agent CLI) yourself, and do not pipe JSON-RPC into patterm's Unix socket via perl / nc / socat / curl. Either path bypasses caller-identity and the new agent reads back as a stray top-level tab instead of your child — call spawn_agent through the MCP transport you were initialised on. Whatever you spawn is yours to clean up — see help('lifecycle').",
 			RelatedTools: []string{"spawn_agent", "spawn_process", "start_process", "restart_process", "close_process"},
 		}
 	case "lifecycle":
@@ -1123,7 +1319,7 @@ func helpFor(topic string) mcp.HelpResponse {
 	case "inspection":
 		return mcp.HelpResponse{
 			Topic:        "inspection",
-			Content:      "get_process_output gives you the visible pane (grid mode) or a byte slice from since_offset (stream mode). list_processes is for the whole session. get_project_status batches everything you need to orient yourself.",
+			Content:      "get_process_output gives you canonical terminal text by default: the visible pane (grid mode) or recent stream text from since_offset (stream mode), with ANSI/control noise, borders, duplicate status churn, and volatile timers removed. Use raw:true only when you need diagnostic PTY bytes; include_meta:true restores cursor, geometry, and screen-version fields. list_processes is for the whole session. get_project_status batches everything you need to orient yourself.",
 			RelatedTools: []string{"list_processes", "get_process_status", "get_process_output", "search_output", "wait_for_pattern", "get_project_status"},
 		}
 	case "io":
@@ -1134,15 +1330,16 @@ func helpFor(topic string) mcp.HelpResponse {
 		}
 	case "coordination":
 		return mcp.HelpResponse{
-			Topic:        "coordination",
-			Content:      "send_message tags the message with the caller's role (parent → [orchestrator], child → [sub-agent:<name>]). Siblings must route through their parent. request_human_attention raises a UI notification when you can't safely decide.",
-			RelatedTools: []string{"send_message", "request_human_attention"},
+			Topic: "coordination",
+			Content: "send_message tags the message with the caller's role (parent → [orchestrator], child → [sub-agent:<name>]). Siblings must route through their parent. request_human_attention raises a UI notification when you can't safely decide.\n\n" +
+				"Reply routing: a sub-agent's reply to your send_message lands in YOUR pane tagged `[sub-agent:<name>]`, not in the sub-agent's output. Anti-pattern: `wait_for_pattern(sub_agent, …)` to wait for a reply — the sub-agent is already idle, its output won't change, and the call spins to timeout. Pattern: send_message → timer_fire_when_idle_any([sub_agent_id], body=\"[system] sub-agent finished\") → when the timer fires, the reply is already queued as your next user turn (or visible via get_process_output on your own pane).",
+			RelatedTools: []string{"send_message", "request_human_attention", "timer_fire_when_idle_any", "timer_fire_when_idle_all"},
 		}
 	case "scratchpads":
 		return mcp.HelpResponse{
 			Topic:        "scratchpads",
-			Content:      "Project-scoped markdown files. Read returns content + revision; pass that back as expected_revision on write to get last-write-wins-with-detection. Append is unconditional.",
-			RelatedTools: []string{"scratchpad_list", "scratchpad_read", "scratchpad_write", "scratchpad_append"},
+			Content:      "Project-scoped markdown files. Read returns content + revision; pass that back as expected_revision on write to get last-write-wins-with-detection. Append is unconditional; delete removes a pad by name.",
+			RelatedTools: []string{"scratchpad_list", "scratchpad_read", "scratchpad_write", "scratchpad_append", "scratchpad_delete"},
 		}
 	case "timers":
 		return mcp.HelpResponse{
@@ -1161,9 +1358,14 @@ func helpFor(topic string) mcp.HelpResponse {
 		}
 	case "readiness":
 		return mcp.HelpResponse{
-			Topic:        "readiness",
-			Content:      "A pane is 'idle' once nothing has been written to its PTY for ~1s (SPEC §11). Treat idle as a signal to read, not a guarantee of completion. wait_for_pattern lets you wait on a known terminal marker for stronger evidence.",
-			RelatedTools: []string{"wait_for_pattern", "get_process_status"},
+			Topic: "readiness",
+			Content: "A pane is 'idle' once nothing has been written to its PTY for ~1s (SPEC §11). Treat idle as a signal to read, not a guarantee of completion.\n\n" +
+				"Waiting for a sub-agent's reply (canonical pattern):\n" +
+				"  1. send_message(sub_agent_id, request)\n" +
+				"  2. timer_fire_when_idle_any(watched=[sub_agent_id], body=\"[system] sub-agent done\")\n" +
+				"  3. When the timer fires you re-enter as a fresh user turn; the sub-agent's reply is already in your own pane tagged `[sub-agent:<name>]` (read via get_process_output on yourself if you need it explicitly).\n\n" +
+				"wait_for_pattern is for waiting on text a process emits in its OWN output (a shell prompt, a build's \"tests passed\" line). It does NOT see send_message replies, because those land in the caller's pane, not the target's — calling wait_for_pattern on a sub-agent to wait for its reply deadlocks until timeout.",
+			RelatedTools: []string{"wait_for_pattern", "get_process_status", "timer_fire_when_idle_any", "send_message"},
 		}
 	case "permissions":
 		return mcp.HelpResponse{

internal/app/host_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/hjbdev/patterm/internal/mcp"
+	"github.com/hjbdev/patterm/internal/scratchpad"
 )
 
 // mkChild builds a Child without starting a PTY. Use sparingly — the
@@ -134,6 +135,42 @@ func TestWrapSubAgentPromptEmptyStaysEmpty(t *testing.T) {
 	}
 }
 
+func TestMCPContentCapsPreferRecentStreamBytes(t *testing.T) {
+	got, gotBytes, truncated, dropped := capBytesTail([]byte("abcdefghijklmnop"), 6)
+	if got != "klmnop" || gotBytes != 6 || !truncated || dropped != 10 {
+		t.Fatalf("capBytesTail = (%q, %d, %v, %d)", got, gotBytes, truncated, dropped)
+	}
+}
+
+func TestMCPGridCapKeepsHeadAndTail(t *testing.T) {
+	got, gotBytes, truncated, dropped := capTextMiddle("abcdefghijklmnopqrstuvwxyz", 24)
+	if gotBytes != 24 || !truncated || dropped != 2 {
+		t.Fatalf("capTextMiddle metadata = (%d, %v, %d), content %q", gotBytes, truncated, dropped, got)
+	}
+	if !strings.Contains(got, "...[truncated]...") {
+		t.Fatalf("capTextMiddle missing marker: %q", got)
+	}
+}
+
+func TestScratchpadReadPagesLargeContent(t *testing.T) {
+	t.Setenv("XDG_DATA_HOME", t.TempDir())
+	store, err := scratchpad.Open("test-project")
+	if err != nil {
+		t.Fatalf("scratchpad open: %v", err)
+	}
+	if _, err := store.Write("notes.md", "abcdefghijklmnopqrstuvwxyz", ""); err != nil {
+		t.Fatalf("scratchpad write: %v", err)
+	}
+	h := &toolHost{pads: store}
+	res, err := h.ScratchpadRead(mcp.ScratchpadReadArgs{Name: "notes.md", Offset: 5, MaxBytes: 7})
+	if err != nil {
+		t.Fatalf("ScratchpadRead: %v", err)
+	}
+	if res.Content != "fghijkl" || !res.Truncated || res.NextOffset != 12 || res.TotalBytes != 26 {
+		t.Fatalf("ScratchpadRead result = %+v", res)
+	}
+}
+
 func TestHelpLifecycleTopicCoversCleanup(t *testing.T) {
 	resp := helpFor("lifecycle")
 	if resp.Topic != "lifecycle" {

internal/app/idle.go

@@ -118,7 +118,8 @@ func compilePatterns(ps []string) []*regexp.Regexp {
 //   - titleIdleMS: ms since the last OSC title change (0 if no title yet)
 //   - title: current OSC title
 //   - tail: recent output bytes for regex matching
-func classify(cfg *resolvedIdleDetection, exited, exitNonZero bool, idleMS, titleIdleMS int64, title string, tail []byte) (IdleState, string) {
+//   - screen: current rendered screen text for persistent prompt matching
+func classify(cfg *resolvedIdleDetection, exited, exitNonZero bool, idleMS, titleIdleMS int64, title string, tail, screen []byte) (IdleState, string) {
 	if exited {
 		if exitNonZero {
 			return StateError, "process exited non-zero"
@@ -128,14 +129,14 @@ func classify(cfg *resolvedIdleDetection, exited, exitNonZero bool, idleMS, titl
 	if cfg == nil {
 		cfg = &resolvedIdleDetection{strategy: StrategyOutputActivity, idleThresholdMS: defaultIdleThresholdMS}
 	}
-	if len(tail) > 0 {
-		if matchAny(cfg.errorRegexes, tail) {
+	if len(tail) > 0 || len(screen) > 0 {
+		if matchAny(cfg.errorRegexes, tail, screen) {
 			return StateError, "error regex matched"
 		}
-		if matchAny(cfg.permissionRegexes, tail) {
+		if matchAny(cfg.permissionRegexes, tail, screen) {
 			return StatePermission, "permission regex matched"
 		}
-		if matchAny(cfg.thinkingRegexes, tail) {
+		if matchAny(cfg.thinkingRegexes, tail, screen) {
 			return StateThinking, "thinking regex matched"
 		}
 	}
@@ -172,10 +173,12 @@ func baseStateFromIdleMS(idleMS, threshold int64) (IdleState, string) {
 	return StateIdle, "quiet for threshold"
 }
 
-func matchAny(res []*regexp.Regexp, tail []byte) bool {
+func matchAny(res []*regexp.Regexp, texts ...[]byte) bool {
 	for _, re := range res {
-		if re.Match(tail) {
-			return true
+		for _, text := range texts {
+			if len(text) > 0 && re.Match(text) {
+				return true
+			}
 		}
 	}
 	return false

internal/app/idle_test.go

@@ -30,7 +30,7 @@ func TestClassifyOutputActivity(t *testing.T) {
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
-			got, _ := classify(cfg, false, false, tc.idleMS, 0, "", nil)
+			got, _ := classify(cfg, false, false, tc.idleMS, 0, "", nil, nil)
 			if got != tc.want {
 				t.Fatalf("got %q want %q", got, tc.want)
 			}
@@ -41,22 +41,37 @@ func TestClassifyOutputActivity(t *testing.T) {
 func TestClassifyTitleStability(t *testing.T) {
 	cfg := &resolvedIdleDetection{strategy: StrategyOSCTitleStability, idleThresholdMS: 2000}
 	// Title change recent → working.
-	if got, _ := classify(cfg, false, false, 9999, 500, "step 3", nil); got != StateWorking {
+	if got, _ := classify(cfg, false, false, 9999, 500, "step 3", nil, nil); got != StateWorking {
 		t.Fatalf("recent title change: got %q", got)
 	}
 	// Title stable past threshold → idle.
-	if got, _ := classify(cfg, false, false, 9999, 5000, "step 3", nil); got != StateIdle {
+	if got, _ := classify(cfg, false, false, 9999, 5000, "step 3", nil, nil); got != StateIdle {
 		t.Fatalf("stable title: got %q", got)
 	}
 	// No title yet: fall back to output activity.
-	if got, _ := classify(cfg, false, false, 100, 0, "", nil); got != StateWorking {
+	if got, _ := classify(cfg, false, false, 100, 0, "", nil, nil); got != StateWorking {
 		t.Fatalf("no title yet, recent output: got %q", got)
 	}
-	if got, _ := classify(cfg, false, false, 5000, 0, "", nil); got != StateIdle {
+	if got, _ := classify(cfg, false, false, 5000, 0, "", nil, nil); got != StateIdle {
 		t.Fatalf("no title yet, output idle: got %q", got)
 	}
 }
 
+func TestClassifyTitleStabilityThinkingPatternOverridesIdle(t *testing.T) {
+	cfg := &resolvedIdleDetection{
+		strategy:        StrategyOSCTitleStability,
+		idleThresholdMS: 2000,
+		thinkingRegexes: []*regexp.Regexp{mustCompile(t, `(?i)esc to interrupt`)},
+	}
+	screen := []byte("• Working (5s • esc to interrupt)")
+	if got, _ := classify(cfg, false, false, 9999, 5000, "codex", nil, screen); got != StateThinking {
+		t.Fatalf("thinking screen marker: got %q want %q", got, StateThinking)
+	}
+	if got, _ := classify(cfg, false, false, 9999, 5000, "codex", nil, []byte(">_")); got != StateIdle {
+		t.Fatalf("stable title without marker: got %q want %q", got, StateIdle)
+	}
+}
+
 func TestClassifyTitleStatus(t *testing.T) {
 	cfg := &resolvedIdleDetection{
 		strategy:        StrategyOSCTitleStatus,
@@ -67,46 +82,51 @@ func TestClassifyTitleStatus(t *testing.T) {
 			"error":      StateError,
 		},
 	}
-	if got, _ := classify(cfg, false, false, 9999, 500, "Thinking…", nil); got != StateThinking {
+	if got, _ := classify(cfg, false, false, 9999, 500, "Thinking…", nil, nil); got != StateThinking {
 		t.Fatalf("thinking title: got %q", got)
 	}
-	if got, _ := classify(cfg, false, false, 9999, 500, "Waiting for permission", nil); got != StatePermission {
+	if got, _ := classify(cfg, false, false, 9999, 500, "Waiting for permission", nil, nil); got != StatePermission {
 		t.Fatalf("permission title: got %q", got)
 	}
 	// No match in map → fall back to stability.
-	if got, _ := classify(cfg, false, false, 9999, 5000, "ready", nil); got != StateIdle {
+	if got, _ := classify(cfg, false, false, 9999, 5000, "ready", nil, nil); got != StateIdle {
 		t.Fatalf("unmatched title, stable: got %q", got)
 	}
 }
 
 func TestClassifyPromoterRegex(t *testing.T) {
 	cfg := &resolvedIdleDetection{
-		strategy:           StrategyOutputActivity,
-		idleThresholdMS:    2000,
-		permissionRegexes:  []*regexp.Regexp{mustCompile(t, `Approve\?`)},
-		errorRegexes:       []*regexp.Regexp{mustCompile(t, `panic:`)},
-		thinkingRegexes:    []*regexp.Regexp{mustCompile(t, `Thinking`)},
+		strategy:          StrategyOutputActivity,
+		idleThresholdMS:   2000,
+		permissionRegexes: []*regexp.Regexp{mustCompile(t, `Approve\?`)},
+		errorRegexes:      []*regexp.Regexp{mustCompile(t, `panic:`)},
+		thinkingRegexes:   []*regexp.Regexp{mustCompile(t, `Thinking`)},
 	}
 	// Permission promoter beats idle.
-	if got, _ := classify(cfg, false, false, 5000, 0, "", []byte("Approve? [y/n]")); got != StatePermission {
+	if got, _ := classify(cfg, false, false, 5000, 0, "", []byte("Approve? [y/n]"), nil); got != StatePermission {
 		t.Fatalf("permission promoter: got %q", got)
 	}
 	// Error trumps permission.
-	if got, _ := classify(cfg, false, false, 5000, 0, "", []byte("panic: bad\nApprove?")); got != StateError {
+	if got, _ := classify(cfg, false, false, 5000, 0, "", []byte("panic: bad\nApprove?"), nil); got != StateError {
 		t.Fatalf("error promoter beats permission: got %q", got)
 	}
 	// Thinking promoter on idle output.
-	if got, _ := classify(cfg, false, false, 5000, 0, "", []byte("Thinking…")); got != StateThinking {
+	if got, _ := classify(cfg, false, false, 5000, 0, "", []byte("Thinking…"), nil); got != StateThinking {
 		t.Fatalf("thinking promoter: got %q", got)
 	}
+	// Rendered-screen prompts still promote even when the raw tail no
+	// longer contains the original prompt bytes.
+	if got, _ := classify(cfg, false, false, 100, 0, "", []byte("Calling patterm..."), []byte("Approve? [y/n]")); got != StatePermission {
+		t.Fatalf("screen permission promoter: got %q", got)
+	}
 }
 
 func TestClassifyExitTerminal(t *testing.T) {
 	cfg := &resolvedIdleDetection{strategy: StrategyOutputActivity, idleThresholdMS: 2000}
-	if got, _ := classify(cfg, true, true, 0, 0, "", nil); got != StateError {
+	if got, _ := classify(cfg, true, true, 0, 0, "", nil, nil); got != StateError {
 		t.Fatalf("non-zero exit: got %q", got)
 	}
-	if got, _ := classify(cfg, true, false, 0, 0, "", nil); got != StateIdle {
+	if got, _ := classify(cfg, true, false, 0, 0, "", nil, nil); got != StateIdle {
 		t.Fatalf("clean exit: got %q", got)
 	}
 }

internal/app/launch.go

@@ -261,15 +261,11 @@ func (l *Launcher) LaunchTerminal(argv []string, displayName, parentID, workDir
 }
 
 func (l *Launcher) writeMCPConfig(identity string) (string, error) {
-	dir, err := preset.ConfigDir()
+	dir, err := mcpRuntimeDir(identity)
 	if err != nil {
 		return "", err
 	}
-	dir = filepath.Join(dir, "mcp")
-	if err := os.MkdirAll(dir, 0o700); err != nil {
-		return "", err
-	}
-	path := filepath.Join(dir, identity+".json")
+	path := filepath.Join(dir, "mcp.json")
 	cfg := map[string]any{
 		"mcpServers": map[string]any{
 			"patterm": map[string]any{

internal/app/launch_test.go

@@ -0,0 +1,30 @@
+package app
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestWriteMCPConfigUsesRuntimeDir(t *testing.T) {
+	runtimeDir := t.TempDir()
+	configHome := filepath.Join(t.TempDir(), "config")
+	t.Setenv("XDG_RUNTIME_DIR", runtimeDir)
+	t.Setenv("XDG_CONFIG_HOME", configHome)
+
+	l := &Launcher{bin: "patterm", mcpSocket: "/tmp/patterm.sock"}
+	path, err := l.writeMCPConfig("abc123")
+	if err != nil {
+		t.Fatalf("writeMCPConfig: %v", err)
+	}
+	if !strings.HasPrefix(path, filepath.Join(runtimeDir, "patterm", "agents", "abc123")) {
+		t.Fatalf("path = %q, want under runtime dir", path)
+	}
+	if _, err := os.Stat(path); err != nil {
+		t.Fatalf("config file stat: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(configHome, "patterm")); !os.IsNotExist(err) {
+		t.Fatalf("writeMCPConfig created XDG config dir or unexpected stat error: %v", err)
+	}
+}

internal/app/layout_test.go

@@ -14,10 +14,10 @@ func TestTerminalLayoutWideUsesMainViewport(t *testing.T) {
 	if l.childCols() != 91 {
 		t.Fatalf("child cols: got %d want 91", l.childCols())
 	}
-	if l.childRows() != 37 {
-		t.Fatalf("child rows: got %d want 37", l.childRows())
+	if l.childRows() != 36 {
+		t.Fatalf("child rows: got %d want 36", l.childRows())
 	}
-	if l.mainTop != 3 || l.statusRow != 40 {
+	if l.mainTop != 4 || l.statusRow != 40 {
 		t.Fatalf("unexpected vertical chrome: mainTop=%d statusRow=%d", l.mainTop, l.statusRow)
 	}
 }
@@ -30,8 +30,8 @@ func TestTerminalLayoutNarrowHidesSidebar(t *testing.T) {
 	if l.childCols() != 38 {
 		t.Fatalf("child cols: got %d want 38", l.childCols())
 	}
-	if l.childRows() != 9 {
-		t.Fatalf("child rows: got %d want 9", l.childRows())
+	if l.childRows() != 8 {
+		t.Fatalf("child rows: got %d want 8", l.childRows())
 	}
 }
 
@@ -46,13 +46,13 @@ func TestSpawnSizingUsesViewportDimensions(t *testing.T) {
 	l := newTerminalLayout(120, 40)
 	launcher := NewLauncher(nil, "", l.childCols(), l.childRows())
 	cols, rows := launcher.size()
-	if cols != 91 || rows != 37 {
-		t.Fatalf("launcher size: got %dx%d want 91x37", cols, rows)
+	if cols != 91 || rows != 36 {
+		t.Fatalf("launcher size: got %dx%d want 91x36", cols, rows)
 	}
 
 	host := newToolHost(nil, nil, nil, preset.Set{}, nil, l.childCols(), l.childRows())
 	cols, rows = host.size()
-	if cols != 91 || rows != 37 {
-		t.Fatalf("tool host size: got %dx%d want 91x37", cols, rows)
+	if cols != 91 || rows != 36 {
+		t.Fatalf("tool host size: got %dx%d want 91x36", cols, rows)
 	}
 }

internal/app/marquee.go

@@ -0,0 +1,123 @@
+package app
+
+import (
+	"sync"
+	"time"
+)
+
+// Phase ordering of the marquee state machine: hold the head, scroll
+// one cell per marqueeStep until the tail is visible, hold the tail,
+// snap back to the head.
+const (
+	phaseHoldStart = iota
+	phaseScroll
+	phaseHoldEnd
+)
+
+const (
+	marqueeHoldStart = time.Second
+	marqueeStep      = 150 * time.Millisecond
+	marqueeHoldEnd   = time.Second
+)
+
+// marqueeState drives the focused sidebar row's pause-scroll-pause
+// animation. State is wall-clock anchored (since), not tick-count
+// anchored, so a missed tick yields a slightly later frame rather
+// than a skipped one.
+type marqueeState struct {
+	mu      sync.Mutex
+	id      string
+	nameLen int
+	budget  int
+	state   int
+	offset  int
+	since   time.Time
+}
+
+// step advances the state machine for the row identified by id with
+// the given visible name length (in runes) and column budget. It
+// returns the current scroll offset, whether the row is animating
+// (i.e. nameLen > budget), and how long until the next visual change.
+//
+// When id changes, or nameLen <= budget, the state machine resets to
+// phaseHoldStart with offset 0 anchored at now.
+func (m *marqueeState) step(id string, nameLen, budget int, now time.Time) (offset int, animating bool, nextWake time.Duration) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if id != m.id || nameLen != m.nameLen || budget != m.budget {
+		m.id = id
+		m.nameLen = nameLen
+		m.budget = budget
+		m.state = phaseHoldStart
+		m.offset = 0
+		m.since = now
+	}
+
+	if nameLen <= budget || budget <= 0 {
+		return 0, false, 0
+	}
+
+	maxOffset := nameLen - budget
+
+	for {
+		elapsed := now.Sub(m.since)
+		switch m.state {
+		case phaseHoldStart:
+			if elapsed < marqueeHoldStart {
+				return 0, true, marqueeHoldStart - elapsed
+			}
+			m.state = phaseScroll
+			m.since = m.since.Add(marqueeHoldStart)
+			continue
+		case phaseScroll:
+			steps := int(elapsed / marqueeStep)
+			if steps >= maxOffset {
+				m.offset = maxOffset
+				m.state = phaseHoldEnd
+				m.since = m.since.Add(time.Duration(maxOffset) * marqueeStep)
+				continue
+			}
+			m.offset = steps
+			rem := marqueeStep - (elapsed % marqueeStep)
+			return m.offset, true, rem
+		case phaseHoldEnd:
+			if elapsed < marqueeHoldEnd {
+				return maxOffset, true, marqueeHoldEnd - elapsed
+			}
+			m.state = phaseHoldStart
+			m.offset = 0
+			m.since = m.since.Add(marqueeHoldEnd)
+			continue
+		default:
+			m.state = phaseHoldStart
+			m.offset = 0
+			m.since = now
+			return 0, true, marqueeHoldStart
+		}
+	}
+}
+
+// active reports whether the marquee currently has an overflowing row
+// to animate. The marquee ticker goroutine uses this to gate dirty
+// flag flips so an idle sidebar costs nothing.
+func (m *marqueeState) active() bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.id != "" && m.nameLen > m.budget && m.budget > 0
+}
+
+// reset clears all state, forcing the next step() call to start a
+// fresh phaseHoldStart. Call this when focus changes so the newly
+// focused row begins with a full head-hold instead of inheriting
+// whatever phase the previous focus was in.
+func (m *marqueeState) reset() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.id = ""
+	m.nameLen = 0
+	m.budget = 0
+	m.state = phaseHoldStart
+	m.offset = 0
+	m.since = time.Time{}
+}

internal/app/marquee_test.go

@@ -0,0 +1,161 @@
+package app
+
+import (
+	"testing"
+	"time"
+)
+
+func TestMarqueeStepFits(t *testing.T) {
+	var m marqueeState
+	now := time.Unix(0, 0)
+	off, animating, _ := m.step("a", 5, 10, now)
+	if animating {
+		t.Fatalf("expected no animation when name fits in budget")
+	}
+	if off != 0 {
+		t.Fatalf("expected offset 0, got %d", off)
+	}
+}
+
+func TestMarqueePhaseProgression(t *testing.T) {
+	var m marqueeState
+	// name 10 runes, budget 5 → maxOffset = 5.
+	const nameLen, budget = 10, 5
+	t0 := time.Unix(0, 0)
+
+	// At t0: phaseHoldStart, offset 0, animating.
+	off, anim, wake := m.step("row", nameLen, budget, t0)
+	if off != 0 || !anim || wake != marqueeHoldStart {
+		t.Fatalf("t0: off=%d anim=%v wake=%v", off, anim, wake)
+	}
+
+	// Just before hold expires: still offset 0.
+	off, anim, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart-time.Millisecond))
+	if off != 0 || !anim {
+		t.Fatalf("pre-expiry hold: off=%d anim=%v", off, anim)
+	}
+
+	// At hold expiry + 1 step: should have transitioned to scroll, offset 1.
+	off, anim, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+marqueeStep))
+	if !anim || off != 1 {
+		t.Fatalf("first scroll step: off=%d anim=%v", off, anim)
+	}
+
+	// Mid-scroll: offset == 3.
+	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+3*marqueeStep))
+	if off != 3 {
+		t.Fatalf("mid scroll: off=%d", off)
+	}
+
+	// Tail reached: offset == maxOffset == 5.
+	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+5*marqueeStep+time.Millisecond))
+	if off != 5 {
+		t.Fatalf("tail: off=%d", off)
+	}
+
+	// Hold-end window still pegged at maxOffset.
+	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+5*marqueeStep+marqueeHoldEnd/2))
+	if off != 5 {
+		t.Fatalf("hold-end mid: off=%d", off)
+	}
+
+	// After hold-end: snap back to offset 0.
+	off, _, _ = m.step("row", nameLen, budget, t0.Add(marqueeHoldStart+5*marqueeStep+marqueeHoldEnd+time.Millisecond))
+	if off != 0 {
+		t.Fatalf("snap back: off=%d", off)
+	}
+}
+
+func TestMarqueeIDChangeResets(t *testing.T) {
+	var m marqueeState
+	t0 := time.Unix(0, 0)
+	_, _, _ = m.step("a", 10, 5, t0)
+	// Advance well into scroll for row "a".
+	_, _, _ = m.step("a", 10, 5, t0.Add(marqueeHoldStart+3*marqueeStep))
+	// Now focus moves to "b": offset must reset to 0 and phase to hold-start.
+	off, anim, wake := m.step("b", 10, 5, t0.Add(marqueeHoldStart+3*marqueeStep))
+	if off != 0 || !anim || wake != marqueeHoldStart {
+		t.Fatalf("id reset: off=%d anim=%v wake=%v", off, anim, wake)
+	}
+}
+
+func TestMarqueeActive(t *testing.T) {
+	var m marqueeState
+	if m.active() {
+		t.Fatalf("fresh marquee should not be active")
+	}
+	_, _, _ = m.step("row", 10, 5, time.Unix(0, 0))
+	if !m.active() {
+		t.Fatalf("expected active after overflow step")
+	}
+	_, _, _ = m.step("row", 4, 5, time.Unix(0, 0))
+	if m.active() {
+		t.Fatalf("should not be active when name fits")
+	}
+}
+
+func TestMarqueeReset(t *testing.T) {
+	var m marqueeState
+	_, _, _ = m.step("row", 10, 5, time.Unix(0, 0))
+	m.reset()
+	if m.active() {
+		t.Fatalf("expected inactive after reset")
+	}
+	// After reset, stepping the same id starts fresh.
+	off, _, wake := m.step("row", 10, 5, time.Unix(5, 0))
+	if off != 0 || wake != marqueeHoldStart {
+		t.Fatalf("post-reset start: off=%d wake=%v", off, wake)
+	}
+}
+
+func TestFitName(t *testing.T) {
+	cases := []struct {
+		name, in string
+		budget   int
+		want     string
+	}{
+		{"fits", "abc", 5, "abc"},
+		{"exact", "abcde", 5, "abcde"},
+		{"truncate", "abcdef", 5, "abcd…"},
+		{"budget1", "abcdef", 1, "…"},
+		{"budget0", "abc", 0, ""},
+		{"unicode", "αβγδεζη", 4, "αβγ…"},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			got := fitName(c.in, c.budget)
+			if got != c.want {
+				t.Fatalf("fitName(%q, %d) = %q want %q", c.in, c.budget, got, c.want)
+			}
+		})
+	}
+}
+
+func TestMarqueeWindow(t *testing.T) {
+	got := marqueeWindow("abcdefgh", 4, 2)
+	if got != "cdef" {
+		t.Fatalf("window = %q", got)
+	}
+	// Clamp end-of-string overflow.
+	got = marqueeWindow("abcdef", 4, 10)
+	if got != "cdef" {
+		t.Fatalf("clamped window = %q", got)
+	}
+}
+
+func TestClampVisible(t *testing.T) {
+	// Plain string longer than width.
+	if got := clampVisible("abcdef", 3); visibleLen(got) != 3 {
+		t.Fatalf("plain clamp visible = %d (%q)", visibleLen(got), got)
+	}
+	// Already-fitting string is unchanged.
+	if got := clampVisible("abc", 5); got != "abc" {
+		t.Fatalf("unchanged = %q", got)
+	}
+	// SGR-wrapped string: visible portion must be <= width.
+	in := "\x1b[1mhello\x1b[0m world"
+	got := clampVisible(in, 5)
+	if visibleLen(got) != 5 {
+		t.Fatalf("sgr clamp visible = %d (%q)", visibleLen(got), got)
+	}
+}

internal/app/metrics.go

@@ -0,0 +1,462 @@
+package app
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+	"time"
+)
+
+// metricsTracker collects per-hot-path counters and timings. All
+// fields are atomic so callers can record from the per-PTY-chunk path
+// without taking a lock. Enabled only when --profile is set.
+//
+// Sampled rates ("X per second", "p99 latency") are not tracked here
+// directly — the snapshotter goroutine writes a row to metrics.jsonl
+// every second, and analysis tools compute rates from the deltas.
+// Aggregate totals are written to metrics.json on shutdown.
+type metricsTracker struct {
+	startedAt time.Time
+
+	// PTY chunk arrival → stdout write pipeline (per OnPTYOut call).
+	ptyChunks      atomic.Int64
+	ptyBytes       atomic.Int64
+	onPTYOutNs     atomic.Int64
+	onPTYOutMaxNs  atomic.Int64
+	onPTYOutDrops  atomic.Int64 // chunks for non-focused children — fast-path returns
+	stdoutWrites   atomic.Int64
+	stdoutBytes    atomic.Int64
+	stdoutNs       atomic.Int64
+	stdoutMaxNs    atomic.Int64
+
+	// Viewport renderer (state-machine over child PTY bytes).
+	renderCalls atomic.Int64
+	renderNs    atomic.Int64
+	renderMaxNs atomic.Int64
+
+	// CGO into libghostty-vt (counted from pumpChild).
+	emuWriteCalls atomic.Int64
+	emuWriteNs    atomic.Int64
+	emuWriteMaxNs atomic.Int64
+	emuTitleCalls atomic.Int64
+	emuTitleNs    atomic.Int64
+	emuTitleSkips atomic.Int64 // OSC-gate fast path — title poll skipped
+
+	// Chrome paint pipeline.
+	sidebarDraws     atomic.Int64
+	sidebarCacheHits atomic.Int64
+	sidebarNs        atomic.Int64
+	sidebarMaxNs     atomic.Int64
+
+	tabbarDraws     atomic.Int64
+	tabbarCacheHits atomic.Int64
+	tabbarNs        atomic.Int64
+
+	statusDraws     atomic.Int64
+	statusCacheHits atomic.Int64
+	statusNs        atomic.Int64
+
+	// Snapshot replay (focus / spawn / nudge).
+	snapshotReplays atomic.Int64
+	snapshotNs      atomic.Int64
+	snapshotMaxNs   atomic.Int64
+
+	// Chrome ticker — distinguishes useful work from idle wakeups.
+	tickerFires      atomic.Int64
+	tickerIdleFires  atomic.Int64 // nothing dirty when the ticker fired
+
+	// Output destination (set when enabled).
+	rowFile *os.File // metrics.jsonl
+	dir     string
+}
+
+// newMetricsTracker creates an enabled tracker writing to <dir>/.
+// Returns nil + nil err if dir is empty (feature off). Caller must
+// call tracker.run(ctx) in a goroutine and tracker.close() at exit.
+func newMetricsTracker(dir string) (*metricsTracker, error) {
+	if dir == "" {
+		return nil, nil
+	}
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return nil, err
+	}
+	row, err := os.Create(filepath.Join(dir, "metrics.jsonl"))
+	if err != nil {
+		return nil, err
+	}
+	return &metricsTracker{
+		startedAt: time.Now(),
+		rowFile:   row,
+		dir:       dir,
+	}, nil
+}
+
+// observeMax updates dst to max(dst, v) using a CAS loop. Atomic max
+// isn't a hardware primitive on most CPUs; this is the standard idiom.
+// Spurious wakeups can race but the result settles at the true max.
+func observeMax(dst *atomic.Int64, v int64) {
+	for {
+		old := dst.Load()
+		if v <= old {
+			return
+		}
+		if dst.CompareAndSwap(old, v) {
+			return
+		}
+	}
+}
+
+// recordPTYOut is called once at the end of each OnPTYOut invocation.
+// `dur` is the full per-chunk wall time (renderer + stdout + chrome
+// signals); `bytes` is the chunk's byte count.
+func (m *metricsTracker) recordPTYOut(dur time.Duration, bytes int) {
+	if m == nil {
+		return
+	}
+	m.ptyChunks.Add(1)
+	m.ptyBytes.Add(int64(bytes))
+	ns := dur.Nanoseconds()
+	m.onPTYOutNs.Add(ns)
+	observeMax(&m.onPTYOutMaxNs, ns)
+}
+
+func (m *metricsTracker) recordPTYOutDrop() {
+	if m == nil {
+		return
+	}
+	m.onPTYOutDrops.Add(1)
+}
+
+func (m *metricsTracker) recordRender(dur time.Duration) {
+	if m == nil {
+		return
+	}
+	m.renderCalls.Add(1)
+	ns := dur.Nanoseconds()
+	m.renderNs.Add(ns)
+	observeMax(&m.renderMaxNs, ns)
+}
+
+func (m *metricsTracker) recordStdout(dur time.Duration, bytes int) {
+	if m == nil {
+		return
+	}
+	m.stdoutWrites.Add(1)
+	m.stdoutBytes.Add(int64(bytes))
+	ns := dur.Nanoseconds()
+	m.stdoutNs.Add(ns)
+	observeMax(&m.stdoutMaxNs, ns)
+}
+
+func (m *metricsTracker) recordEmuWrite(dur time.Duration) {
+	if m == nil {
+		return
+	}
+	m.emuWriteCalls.Add(1)
+	ns := dur.Nanoseconds()
+	m.emuWriteNs.Add(ns)
+	observeMax(&m.emuWriteMaxNs, ns)
+}
+
+func (m *metricsTracker) recordEmuTitle(dur time.Duration, skipped bool) {
+	if m == nil {
+		return
+	}
+	if skipped {
+		m.emuTitleSkips.Add(1)
+		return
+	}
+	m.emuTitleCalls.Add(1)
+	m.emuTitleNs.Add(dur.Nanoseconds())
+}
+
+func (m *metricsTracker) recordSidebar(dur time.Duration, cacheHit bool) {
+	if m == nil {
+		return
+	}
+	m.sidebarDraws.Add(1)
+	if cacheHit {
+		m.sidebarCacheHits.Add(1)
+	}
+	ns := dur.Nanoseconds()
+	m.sidebarNs.Add(ns)
+	observeMax(&m.sidebarMaxNs, ns)
+}
+
+func (m *metricsTracker) recordTabbar(dur time.Duration, cacheHit bool) {
+	if m == nil {
+		return
+	}
+	m.tabbarDraws.Add(1)
+	if cacheHit {
+		m.tabbarCacheHits.Add(1)
+	}
+	m.tabbarNs.Add(dur.Nanoseconds())
+}
+
+func (m *metricsTracker) recordStatus(dur time.Duration, cacheHit bool) {
+	if m == nil {
+		return
+	}
+	m.statusDraws.Add(1)
+	if cacheHit {
+		m.statusCacheHits.Add(1)
+	}
+	m.statusNs.Add(dur.Nanoseconds())
+}
+
+func (m *metricsTracker) recordSnapshot(dur time.Duration) {
+	if m == nil {
+		return
+	}
+	m.snapshotReplays.Add(1)
+	ns := dur.Nanoseconds()
+	m.snapshotNs.Add(ns)
+	observeMax(&m.snapshotMaxNs, ns)
+}
+
+func (m *metricsTracker) recordTickerFire(didWork bool) {
+	if m == nil {
+		return
+	}
+	m.tickerFires.Add(1)
+	if !didWork {
+		m.tickerIdleFires.Add(1)
+	}
+}
+
+// snapshot captures the tracker's current state as a JSON-serialisable
+// map. Suitable for both the per-second JSONL row and the final
+// metrics.json aggregate.
+type metricsSnapshot struct {
+	WallSeconds   float64 `json:"wall_seconds"`
+	PTYChunks     int64   `json:"pty_chunks"`
+	PTYBytes      int64   `json:"pty_bytes"`
+	OnPTYOutNs    int64   `json:"on_pty_out_ns_total"`
+	OnPTYOutMaxNs int64   `json:"on_pty_out_ns_max"`
+	OnPTYOutDrops int64   `json:"on_pty_out_drops"`
+	StdoutWrites  int64   `json:"stdout_writes"`
+	StdoutBytes   int64   `json:"stdout_bytes"`
+	StdoutNs      int64   `json:"stdout_ns_total"`
+	StdoutMaxNs   int64   `json:"stdout_ns_max"`
+
+	RenderCalls int64 `json:"render_calls"`
+	RenderNs    int64 `json:"render_ns_total"`
+	RenderMaxNs int64 `json:"render_ns_max"`
+
+	EmuWriteCalls int64 `json:"emu_write_calls"`
+	EmuWriteNs    int64 `json:"emu_write_ns_total"`
+	EmuWriteMaxNs int64 `json:"emu_write_ns_max"`
+	EmuTitleCalls int64 `json:"emu_title_calls"`
+	EmuTitleNs    int64 `json:"emu_title_ns_total"`
+	EmuTitleSkips int64 `json:"emu_title_skips"`
+
+	SidebarDraws     int64 `json:"sidebar_draws"`
+	SidebarCacheHits int64 `json:"sidebar_cache_hits"`
+	SidebarNs        int64 `json:"sidebar_ns_total"`
+	SidebarMaxNs     int64 `json:"sidebar_ns_max"`
+
+	TabbarDraws     int64 `json:"tabbar_draws"`
+	TabbarCacheHits int64 `json:"tabbar_cache_hits"`
+	TabbarNs        int64 `json:"tabbar_ns_total"`
+
+	StatusDraws     int64 `json:"status_draws"`
+	StatusCacheHits int64 `json:"status_cache_hits"`
+	StatusNs        int64 `json:"status_ns_total"`
+
+	SnapshotReplays int64 `json:"snapshot_replays"`
+	SnapshotNs      int64 `json:"snapshot_ns_total"`
+	SnapshotMaxNs   int64 `json:"snapshot_ns_max"`
+
+	TickerFires     int64 `json:"ticker_fires"`
+	TickerIdleFires int64 `json:"ticker_idle_fires"`
+
+	// Derived rates (computed at snapshot time so consumers don't have
+	// to). All "per_second" values are averaged over wall_seconds.
+	PTYChunksPerSec      float64 `json:"pty_chunks_per_sec"`
+	PTYBytesPerSec       float64 `json:"pty_bytes_per_sec"`
+	OnPTYOutMeanUs       float64 `json:"on_pty_out_mean_us"`
+	StdoutMeanUs         float64 `json:"stdout_mean_us"`
+	EmuWriteMeanUs       float64 `json:"emu_write_mean_us"`
+	SidebarMeanUs        float64 `json:"sidebar_mean_us"`
+	SidebarCacheHitRate  float64 `json:"sidebar_cache_hit_rate"`
+	TabbarCacheHitRate   float64 `json:"tabbar_cache_hit_rate"`
+	StatusCacheHitRate   float64 `json:"status_cache_hit_rate"`
+	EmuTitleSkipRate     float64 `json:"emu_title_skip_rate"`
+	TickerIdleRate       float64 `json:"ticker_idle_rate"`
+	Timestamp            string  `json:"timestamp"`
+}
+
+func (m *metricsTracker) snapshotNow() metricsSnapshot {
+	wall := time.Since(m.startedAt).Seconds()
+	if wall <= 0 {
+		wall = 1
+	}
+	chunks := m.ptyChunks.Load()
+	bytes := m.ptyBytes.Load()
+	onptyTotal := m.onPTYOutNs.Load()
+	stdW := m.stdoutWrites.Load()
+	stdNs := m.stdoutNs.Load()
+	emuW := m.emuWriteCalls.Load()
+	emuWNs := m.emuWriteNs.Load()
+	sbDraws := m.sidebarDraws.Load()
+	sbHits := m.sidebarCacheHits.Load()
+	sbNs := m.sidebarNs.Load()
+	tbDraws := m.tabbarDraws.Load()
+	tbHits := m.tabbarCacheHits.Load()
+	stDraws := m.statusDraws.Load()
+	stHits := m.statusCacheHits.Load()
+	emuTC := m.emuTitleCalls.Load()
+	emuTS := m.emuTitleSkips.Load()
+	tickerF := m.tickerFires.Load()
+	tickerI := m.tickerIdleFires.Load()
+
+	div := func(num, denom int64) float64 {
+		if denom == 0 {
+			return 0
+		}
+		return float64(num) / float64(denom)
+	}
+
+	return metricsSnapshot{
+		WallSeconds:   wall,
+		PTYChunks:     chunks,
+		PTYBytes:      bytes,
+		OnPTYOutNs:    onptyTotal,
+		OnPTYOutMaxNs: m.onPTYOutMaxNs.Load(),
+		OnPTYOutDrops: m.onPTYOutDrops.Load(),
+		StdoutWrites:  stdW,
+		StdoutBytes:   m.stdoutBytes.Load(),
+		StdoutNs:      stdNs,
+		StdoutMaxNs:   m.stdoutMaxNs.Load(),
+
+		RenderCalls: m.renderCalls.Load(),
+		RenderNs:    m.renderNs.Load(),
+		RenderMaxNs: m.renderMaxNs.Load(),
+
+		EmuWriteCalls: emuW,
+		EmuWriteNs:    emuWNs,
+		EmuWriteMaxNs: m.emuWriteMaxNs.Load(),
+		EmuTitleCalls: emuTC,
+		EmuTitleNs:    m.emuTitleNs.Load(),
+		EmuTitleSkips: emuTS,
+
+		SidebarDraws:     sbDraws,
+		SidebarCacheHits: sbHits,
+		SidebarNs:        sbNs,
+		SidebarMaxNs:     m.sidebarMaxNs.Load(),
+
+		TabbarDraws:     tbDraws,
+		TabbarCacheHits: tbHits,
+		TabbarNs:        m.tabbarNs.Load(),
+
+		StatusDraws:     stDraws,
+		StatusCacheHits: stHits,
+		StatusNs:        m.statusNs.Load(),
+
+		SnapshotReplays: m.snapshotReplays.Load(),
+		SnapshotNs:      m.snapshotNs.Load(),
+		SnapshotMaxNs:   m.snapshotMaxNs.Load(),
+
+		TickerFires:     tickerF,
+		TickerIdleFires: tickerI,
+
+		PTYChunksPerSec:     float64(chunks) / wall,
+		PTYBytesPerSec:      float64(bytes) / wall,
+		OnPTYOutMeanUs:      div(onptyTotal/1000, chunks),
+		StdoutMeanUs:        div(stdNs/1000, stdW),
+		EmuWriteMeanUs:      div(emuWNs/1000, emuW),
+		SidebarMeanUs:       div(sbNs/1000, sbDraws),
+		SidebarCacheHitRate: div(sbHits, sbDraws),
+		TabbarCacheHitRate:  div(tbHits, tbDraws),
+		StatusCacheHitRate:  div(stHits, stDraws),
+		EmuTitleSkipRate:    div(emuTS, emuTC+emuTS),
+		TickerIdleRate:      div(tickerI, tickerF),
+		Timestamp:           time.Now().Format(time.RFC3339Nano),
+	}
+}
+
+// run is the snapshotter goroutine: write a JSONL row every second
+// until ctx is cancelled. Stops cleanly without flushing partial
+// rows.
+func (m *metricsTracker) run(ctx context.Context) {
+	if m == nil {
+		return
+	}
+	enc := json.NewEncoder(m.rowFile)
+	ticker := time.NewTicker(time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			snap := m.snapshotNow()
+			_ = enc.Encode(snap)
+		}
+	}
+}
+
+// close writes the final aggregate snapshot to metrics.json + a
+// short human-readable summary.txt, then closes the row file. Safe
+// to call on a nil receiver.
+func (m *metricsTracker) close() {
+	if m == nil {
+		return
+	}
+	snap := m.snapshotNow()
+	if f, err := os.Create(filepath.Join(m.dir, "metrics.json")); err == nil {
+		enc := json.NewEncoder(f)
+		enc.SetIndent("", "  ")
+		_ = enc.Encode(snap)
+		_ = f.Close()
+	}
+	if f, err := os.Create(filepath.Join(m.dir, "summary.txt")); err == nil {
+		writeSummary(f, snap)
+		_ = f.Close()
+	}
+	if m.rowFile != nil {
+		_ = m.rowFile.Close()
+		m.rowFile = nil
+	}
+}
+
+// writeSummary renders a brief human-readable digest of a snapshot.
+// Designed for `cat summary.txt` after a session — quick orientation
+// before diving into metrics.json / pprof.
+func writeSummary(w *os.File, s metricsSnapshot) {
+	fmt.Fprintf(w, "patterm performance summary\n")
+	fmt.Fprintf(w, "===========================\n\n")
+	fmt.Fprintf(w, "session length:        %.1fs\n", s.WallSeconds)
+	fmt.Fprintf(w, "pty chunks:            %d  (%.1f /s)\n", s.PTYChunks, s.PTYChunksPerSec)
+	fmt.Fprintf(w, "pty bytes:             %d  (%.0f /s, %.1f KiB/s)\n",
+		s.PTYBytes, s.PTYBytesPerSec, s.PTYBytesPerSec/1024)
+	fmt.Fprintf(w, "pty chunks dropped:    %d  (focus not on caller — fast-path return)\n", s.OnPTYOutDrops)
+	fmt.Fprintf(w, "\n")
+	fmt.Fprintf(w, "OnPTYOut mean:         %.1fµs   max: %.1fms\n",
+		s.OnPTYOutMeanUs, float64(s.OnPTYOutMaxNs)/1e6)
+	fmt.Fprintf(w, "viewport.Render calls: %d  total %.1fms  max %.1fms\n",
+		s.RenderCalls, float64(s.RenderNs)/1e6, float64(s.RenderMaxNs)/1e6)
+	fmt.Fprintf(w, "stdout writes:         %d  mean %.1fµs  max %.1fms  bytes %d\n",
+		s.StdoutWrites, s.StdoutMeanUs, float64(s.StdoutMaxNs)/1e6, s.StdoutBytes)
+	fmt.Fprintf(w, "\n")
+	fmt.Fprintf(w, "emulator.Write (cgo):  %d  mean %.1fµs  max %.1fms\n",
+		s.EmuWriteCalls, s.EmuWriteMeanUs, float64(s.EmuWriteMaxNs)/1e6)
+	fmt.Fprintf(w, "emulator.Title polls:  %d real, %d gated   skip rate %.1f%%\n",
+		s.EmuTitleCalls, s.EmuTitleSkips, s.EmuTitleSkipRate*100)
+	fmt.Fprintf(w, "\n")
+	fmt.Fprintf(w, "sidebar draws:         %d  mean %.1fµs  max %.1fms  cache-hit %.1f%%\n",
+		s.SidebarDraws, s.SidebarMeanUs, float64(s.SidebarMaxNs)/1e6, s.SidebarCacheHitRate*100)
+	fmt.Fprintf(w, "tabbar draws:          %d  cache-hit %.1f%%\n",
+		s.TabbarDraws, s.TabbarCacheHitRate*100)
+	fmt.Fprintf(w, "status draws:          %d  cache-hit %.1f%%\n",
+		s.StatusDraws, s.StatusCacheHitRate*100)
+	fmt.Fprintf(w, "snapshot replays:      %d  total %.1fms  max %.1fms\n",
+		s.SnapshotReplays, float64(s.SnapshotNs)/1e6, float64(s.SnapshotMaxNs)/1e6)
+	fmt.Fprintf(w, "\n")
+	fmt.Fprintf(w, "chrome ticker:         %d fires, %d idle   idle rate %.1f%%\n",
+		s.TickerFires, s.TickerIdleFires, s.TickerIdleRate*100)
+}

internal/app/metrics_test.go

@@ -0,0 +1,116 @@
+package app
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+func TestMetricsTrackerDisabledByEmptyDir(t *testing.T) {
+	m, err := newMetricsTracker("")
+	if err != nil {
+		t.Fatalf("newMetricsTracker(\"\") err: %v", err)
+	}
+	if m != nil {
+		t.Fatalf("expected nil tracker for empty dir, got %v", m)
+	}
+}
+
+func TestMetricsTrackerRecordsAndWrites(t *testing.T) {
+	dir := t.TempDir()
+	m, err := newMetricsTracker(dir)
+	if err != nil {
+		t.Fatalf("newMetricsTracker: %v", err)
+	}
+	if m == nil {
+		t.Fatal("expected non-nil tracker")
+	}
+
+	m.recordPTYOut(2*time.Millisecond, 1024)
+	m.recordPTYOut(5*time.Millisecond, 4096)
+	m.recordRender(800 * time.Microsecond)
+	m.recordStdout(300*time.Microsecond, 1100)
+	m.recordEmuWrite(150 * time.Microsecond)
+	m.recordEmuTitle(0, true)
+	m.recordEmuTitle(20*time.Microsecond, false)
+	m.recordSidebar(100*time.Microsecond, true)
+	m.recordSidebar(900*time.Microsecond, false)
+	m.recordTabbar(50*time.Microsecond, true)
+	m.recordStatus(40*time.Microsecond, true)
+	m.recordSnapshot(2 * time.Millisecond)
+	m.recordTickerFire(false)
+	m.recordTickerFire(true)
+	m.recordPTYOutDrop()
+
+	m.close()
+
+	// metrics.json should exist and parse, and reflect what we recorded.
+	raw, err := os.ReadFile(filepath.Join(dir, "metrics.json"))
+	if err != nil {
+		t.Fatalf("read metrics.json: %v", err)
+	}
+	var snap metricsSnapshot
+	if err := json.Unmarshal(raw, &snap); err != nil {
+		t.Fatalf("parse metrics.json: %v", err)
+	}
+	if snap.PTYChunks != 2 {
+		t.Errorf("PTYChunks = %d, want 2", snap.PTYChunks)
+	}
+	if snap.PTYBytes != 5120 {
+		t.Errorf("PTYBytes = %d, want 5120", snap.PTYBytes)
+	}
+	if snap.OnPTYOutMaxNs != (5 * time.Millisecond).Nanoseconds() {
+		t.Errorf("OnPTYOutMaxNs = %d, want %d",
+			snap.OnPTYOutMaxNs, (5 * time.Millisecond).Nanoseconds())
+	}
+	if snap.SidebarDraws != 2 {
+		t.Errorf("SidebarDraws = %d, want 2", snap.SidebarDraws)
+	}
+	if snap.SidebarCacheHits != 1 {
+		t.Errorf("SidebarCacheHits = %d, want 1", snap.SidebarCacheHits)
+	}
+	if snap.SidebarCacheHitRate != 0.5 {
+		t.Errorf("SidebarCacheHitRate = %v, want 0.5", snap.SidebarCacheHitRate)
+	}
+	if snap.EmuTitleCalls != 1 || snap.EmuTitleSkips != 1 {
+		t.Errorf("emu title accounting: calls=%d skips=%d, want 1/1",
+			snap.EmuTitleCalls, snap.EmuTitleSkips)
+	}
+	if snap.TickerFires != 2 || snap.TickerIdleFires != 1 {
+		t.Errorf("ticker accounting: fires=%d idle=%d, want 2/1",
+			snap.TickerFires, snap.TickerIdleFires)
+	}
+	if snap.OnPTYOutDrops != 1 {
+		t.Errorf("OnPTYOutDrops = %d, want 1", snap.OnPTYOutDrops)
+	}
+
+	// summary.txt should also be present and non-empty.
+	info, err := os.Stat(filepath.Join(dir, "summary.txt"))
+	if err != nil {
+		t.Fatalf("stat summary.txt: %v", err)
+	}
+	if info.Size() == 0 {
+		t.Fatal("summary.txt is empty")
+	}
+}
+
+func TestMetricsTrackerNilSafe(t *testing.T) {
+	// Every record* method must be safe to call on a nil receiver
+	// because the hot paths use that to avoid an enabled-check.
+	var m *metricsTracker
+	m.recordPTYOut(time.Millisecond, 100)
+	m.recordPTYOutDrop()
+	m.recordRender(time.Microsecond)
+	m.recordStdout(time.Microsecond, 50)
+	m.recordEmuWrite(time.Microsecond)
+	m.recordEmuTitle(time.Microsecond, false)
+	m.recordEmuTitle(0, true)
+	m.recordSidebar(time.Microsecond, true)
+	m.recordTabbar(time.Microsecond, false)
+	m.recordStatus(time.Microsecond, true)
+	m.recordSnapshot(time.Microsecond)
+	m.recordTickerFire(true)
+	m.close()
+}

internal/app/palette_context_test.go

@@ -31,14 +31,17 @@ func findItem(p *paletteState, want string) (int, *paletteItem) {
 
 func TestContextItemsScratchpad(t *testing.T) {
 	p := newPalette(nil, "", "notes.md", preset.Set{})
-	if i, _ := findItem(p, "pad-delete"); i != 0 {
-		t.Fatalf("pad-delete at %d; want top", i)
+	// With the dashed section header gone, pad-edit is the first row;
+	// pad-rename-form follows, with destructive pad-delete last in the
+	// Focused section.
+	if i, _ := findItem(p, "pad-edit"); i != 0 {
+		t.Fatalf("pad-edit at %d; want 0", i)
 	}
 	if _, it := findItem(p, "pad-rename-form"); it == nil || it.action.padName != "notes.md" {
 		t.Fatalf("pad-rename-form missing or wrong padName: %+v", it)
 	}
-	if _, it := findItem(p, "pad-edit"); it == nil {
-		t.Fatalf("pad-edit missing")
+	if i, _ := findItem(p, "pad-delete"); i < 0 {
+		t.Fatalf("pad-delete missing")
 	}
 	// No focused child → no agent/proc context items.
 	if i, _ := findItem(p, "agent-rename-form"); i != -1 {
@@ -80,9 +83,31 @@ func TestContextItemsProcess(t *testing.T) {
 	}
 }
 
+func TestContextItemsTerminalUsesCloseNotStop(t *testing.T) {
+	c := makeFakeChild("tid", "terminal", KindTerminal)
+	p := newPalette([]*Child{c}, "tid", "", preset.Set{})
+	if _, it := findItem(p, "proc-stop"); it == nil || it.label != "Close" {
+		t.Fatalf("terminal close row missing or mislabelled: %+v", it)
+	}
+	if _, it := findItem(p, "proc-restart"); it == nil {
+		t.Fatalf("terminal restart row missing")
+	}
+	if i, _ := findItem(p, "proc-delete"); i != -1 {
+		t.Fatalf("terminal should not show a separate delete/close row, found at %d", i)
+	}
+	for i, it := range p.items {
+		if it.label == "Stop" {
+			t.Fatalf("terminal should not show Stop row, found at %d", i)
+		}
+	}
+}
+
 func TestContextItemsAppearAboveSwitch(t *testing.T) {
-	c := makeFakeChild("pid", "devserver", KindCommand)
-	p := newPalette([]*Child{c}, "pid", "", preset.Set{})
+	// Two children so there's still a non-focused switch entry to compare
+	// against (the focused child is suppressed from the Open section).
+	focused := makeFakeChild("pid", "devserver", KindCommand)
+	other := makeFakeChild("oid", "worker", KindCommand)
+	p := newPalette([]*Child{focused, other}, "pid", "", preset.Set{})
 	procIdx, _ := findItem(p, "proc-rename-form")
 	switchIdx, _ := findItem(p, "switch")
 	if procIdx < 0 || switchIdx < 0 {

internal/app/palette_input_test.go

@@ -47,36 +47,50 @@ func TestPaletteBareEscCancels(t *testing.T) {
 	}
 }
 
+// firstSelectable returns the lowest item index whose action is
+// selectable (not a section header), or -1 if the palette has no
+// selectable rows.
+func firstSelectable(p *paletteState) int {
+	for i, it := range p.items {
+		if it.action.kind != "header" {
+			return i
+		}
+	}
+	return -1
+}
+
 func TestPaletteKittyArrowsNavigate(t *testing.T) {
 	pr := []*preset.Preset{{Name: "a"}, {Name: "b"}, {Name: "c"}}
 	p := newPalette(nil, "", "", preset.Set{Agents: pr})
-	if p.cursor != 0 {
-		t.Fatalf("initial cursor %d", p.cursor)
+	first := firstSelectable(p)
+	if first < 0 || p.cursor != first {
+		t.Fatalf("initial cursor %d, want first selectable %d", p.cursor, first)
 	}
 	// Kitty functional Down arrow.
 	_, _, adv := p.handleInput([]byte("\x1b[57353u"), 0)
 	if adv != 8 {
 		t.Fatalf("advance %d", adv)
 	}
-	if p.cursor != 1 {
-		t.Fatalf("cursor %d after Down, want 1", p.cursor)
+	if p.cursor != first+1 {
+		t.Fatalf("cursor %d after Down, want %d", p.cursor, first+1)
 	}
 	// Kitty functional Up arrow.
 	_, _, _ = p.handleInput([]byte("\x1b[57352u"), 0)
-	if p.cursor != 0 {
-		t.Fatalf("cursor %d after Up, want 0", p.cursor)
+	if p.cursor != first {
+		t.Fatalf("cursor %d after Up, want %d", p.cursor, first)
 	}
 }
 
 func TestPaletteLegacyArrowsStillWork(t *testing.T) {
 	pr := []*preset.Preset{{Name: "a"}, {Name: "b"}}
 	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	first := firstSelectable(p)
 	_, _, adv := p.handleInput([]byte("\x1b[B"), 0)
 	if adv != 3 {
 		t.Fatalf("advance %d", adv)
 	}
-	if p.cursor != 1 {
-		t.Fatalf("cursor %d, want 1", p.cursor)
+	if p.cursor != first+1 {
+		t.Fatalf("cursor %d, want %d", p.cursor, first+1)
 	}
 }
 

internal/app/palette_ux_test.go

@@ -0,0 +1,484 @@
+package app
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/hjbdev/patterm/internal/preset"
+)
+
+// -- Phase 1: naming & dropped global Close list ---------------------
+
+func TestPaletteVerbsAreUnified(t *testing.T) {
+	procs := []*preset.Preset{{Name: "dev"}}
+	agents := []*preset.Preset{{Name: "claude"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: agents, Processes: procs})
+	gotLabels := make([]string, 0, len(p.items))
+	for _, it := range p.items {
+		if it.action.kind == "header" {
+			continue
+		}
+		gotLabels = append(gotLabels, it.label)
+	}
+	joined := strings.Join(gotLabels, "\n")
+
+	mustContain := []string{
+		"Spawn agent: claude",
+		"Spawn process: dev",
+		"Spawn terminal",
+		"Spawn process… (custom)",
+	}
+	for _, want := range mustContain {
+		if !strings.Contains(joined, want) {
+			t.Errorf("missing unified-verb label %q in:\n%s", want, joined)
+		}
+	}
+	// The pre-overhaul verb forms must not appear anywhere.
+	mustNotContain := []string{"Run process:", "New Terminal", "Spawn process… (custom)"}
+	for _, bad := range mustNotContain {
+		if strings.Contains(joined, bad) {
+			t.Errorf("leftover legacy verb %q present in:\n%s", bad, joined)
+		}
+	}
+}
+
+func TestPaletteDropsGlobalCloseList(t *testing.T) {
+	c1 := makeFakeChild("a", "claude", KindAgent)
+	c2 := makeFakeChild("b", "dev", KindCommand)
+	p := newPalette([]*Child{c1, c2}, "", "", preset.Set{})
+	// No focus → no Focused context, so no "kill" / "agent-close" /
+	// "proc-stop" rows should exist at all.
+	for _, kind := range []string{"kill", "agent-close", "proc-stop", "proc-delete"} {
+		if i, _ := findItem(p, kind); i != -1 {
+			t.Fatalf("kind %q present at %d; global Close list should be gone", kind, i)
+		}
+	}
+}
+
+// -- Phase 2: section headers and cursor skip ------------------------
+
+func TestPaletteSectionsSeparatedBySpacers(t *testing.T) {
+	// Section-named dashed headers are gone; groups are visually
+	// separated by a single non-selectable blank row. Verify that the
+	// build emits one such spacer between every pair of adjacent groups
+	// and never a leading spacer.
+	c := makeFakeChild("a", "claude", KindAgent)
+	other := makeFakeChild("b", "worker", KindCommand)
+	p := newPalette([]*Child{c, other}, "a", "",
+		preset.Set{Agents: []*preset.Preset{{Name: "codex"}}})
+
+	if len(p.items) == 0 {
+		t.Fatalf("palette built no items")
+	}
+	if p.items[0].action.kind == "header" {
+		t.Fatalf("first row is a spacer; should be a selectable item")
+	}
+	transitions := 0
+	prevGroup := p.items[0].group
+	for i := 1; i < len(p.items); i++ {
+		it := p.items[i]
+		if it.group != prevGroup {
+			if it.action.kind != "header" || it.label != "" {
+				t.Fatalf("group transition at %d not a blank spacer: %+v", i, it)
+			}
+			transitions++
+			// The row immediately after the spacer must be selectable.
+			if i+1 >= len(p.items) || p.items[i+1].action.kind == "header" {
+				t.Fatalf("spacer at %d not followed by selectable row", i)
+			}
+			prevGroup = p.items[i+1].group
+		}
+		// No dashed banners anywhere.
+		if it.action.kind == "header" && strings.Contains(it.label, "──") {
+			t.Errorf("dashed section header still present at %d: %q", i, it.label)
+		}
+	}
+	if transitions == 0 {
+		t.Fatalf("no section transitions found in palette items")
+	}
+}
+
+func TestPaletteCursorSkipsHeaders(t *testing.T) {
+	pr := []*preset.Preset{{Name: "a"}, {Name: "b"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	// Initial cursor must land on a selectable row, never a header.
+	if p.items[p.cursor].action.kind == "header" {
+		t.Fatalf("initial cursor sits on a header: %+v", p.items[p.cursor])
+	}
+	// Walk to the end with cursorDown; every stop must be selectable.
+	for i := 0; i < len(p.items)*2; i++ {
+		p.cursorDown()
+		if p.items[p.cursor].action.kind == "header" {
+			t.Fatalf("cursorDown landed on a header at index %d", p.cursor)
+		}
+	}
+	// Walk back to top.
+	for i := 0; i < len(p.items)*2; i++ {
+		p.cursorUp()
+		if p.items[p.cursor].action.kind == "header" {
+			t.Fatalf("cursorUp landed on a header at index %d", p.cursor)
+		}
+	}
+}
+
+func TestPaletteEnterOnHeaderIsNoOp(t *testing.T) {
+	pr := []*preset.Preset{{Name: "a"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	// Force the cursor onto a header.
+	for i, it := range p.items {
+		if it.action.kind == "header" {
+			p.cursor = i
+			break
+		}
+	}
+	_, done, _ := p.handleInput([]byte("\r"), 0)
+	if done {
+		t.Fatalf("Enter on header closed palette; expected no-op")
+	}
+}
+
+// -- Phase 3: filter chips & macro coexistence -----------------------
+
+func TestPaletteTabCyclesChip(t *testing.T) {
+	p := newTestPalette()
+	// All → Open
+	_, _, _ = p.handleInput([]byte{'\t'}, 0)
+	if string(p.query) != "sw " {
+		t.Fatalf("Tab #1: query %q, want %q", string(p.query), "sw ")
+	}
+	// Open → Spawn
+	_, _, _ = p.handleInput([]byte{'\t'}, 0)
+	if string(p.query) != "sp " {
+		t.Fatalf("Tab #2: query %q, want %q", string(p.query), "sp ")
+	}
+	// Spawn → Close
+	_, _, _ = p.handleInput([]byte{'\t'}, 0)
+	if string(p.query) != "k " {
+		t.Fatalf("Tab #3: query %q, want %q", string(p.query), "k ")
+	}
+	// Close → All (wraps)
+	_, _, _ = p.handleInput([]byte{'\t'}, 0)
+	if string(p.query) != "" {
+		t.Fatalf("Tab #4 wrap: query %q, want empty", string(p.query))
+	}
+}
+
+func TestPaletteShiftTabCyclesBackwards(t *testing.T) {
+	p := newTestPalette()
+	// Shift-Tab via legacy CSI Z: All → Close
+	_, _, _ = p.handleInput([]byte("\x1b[Z"), 0)
+	if string(p.query) != "k " {
+		t.Fatalf("Shift-Tab: query %q, want %q", string(p.query), "k ")
+	}
+}
+
+func TestPaletteBackspaceThroughTrailingMacro(t *testing.T) {
+	p := newTestPalette()
+	p.query = []rune("sw ")
+	p.rebuild()
+	p.backspace()
+	if string(p.query) != "" {
+		t.Fatalf("backspace through 'sw ' left %q; want empty", string(p.query))
+	}
+}
+
+func TestPaletteMacroPreservesQueryCase(t *testing.T) {
+	// Tab cycling shouldn't downcase the user-typed search text.
+	p := newTestPalette()
+	p.query = []rune("Foo")
+	p.rebuild()
+	_, _, _ = p.handleInput([]byte{'\t'}, 0)
+	if string(p.query) != "sw Foo" {
+		t.Fatalf("query after Tab over 'Foo' = %q; want 'sw Foo'", string(p.query))
+	}
+}
+
+// -- Phase 4: scored matching ----------------------------------------
+
+func TestFuzzyScorePrefixBeatsBoundaryBeatsSubstring(t *testing.T) {
+	prefix, _ := fuzzyScore("spawn agent: foo", "", "spa")
+	boundary, _ := fuzzyScore("hello spam", "", "spa")
+	substring, _ := fuzzyScore("escapade", "", "spa")
+	if !(prefix > boundary && boundary > substring) {
+		t.Fatalf("score ordering wrong: prefix=%d boundary=%d substring=%d", prefix, boundary, substring)
+	}
+}
+
+func TestFuzzyScoreReturnsMatchPositions(t *testing.T) {
+	_, pos := fuzzyScore("spawn process: dev", "", "dev")
+	want := []int{15, 16, 17}
+	if len(pos) != len(want) {
+		t.Fatalf("positions = %v, want %v", pos, want)
+	}
+	for i, p := range pos {
+		if p != want[i] {
+			t.Fatalf("pos[%d] = %d, want %d (full %v)", i, p, want[i], pos)
+		}
+	}
+}
+
+func TestPaletteScoredResultsDropHeaders(t *testing.T) {
+	pr := []*preset.Preset{{Name: "claude"}, {Name: "codex"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	// Type a needle that matches both.
+	p.query = []rune("c")
+	p.rebuild()
+	for _, it := range p.items {
+		if it.action.kind == "header" {
+			t.Fatalf("scored mode should not emit header rows; got %+v", it)
+		}
+	}
+}
+
+func TestPaletteScoringFloatsPrefixMatchToTop(t *testing.T) {
+	// "x" is a prefix of "xtest" preset; it's a scattered-fuzzy match
+	// against many other rows. Scoring should land the prefix match at
+	// the top regardless of group order.
+	pr := []*preset.Preset{
+		{Name: "alpha"},
+		{Name: "xtest"},
+		{Name: "beta"},
+	}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	p.query = []rune("xt")
+	p.rebuild()
+	if len(p.items) == 0 {
+		t.Fatalf("no scored items for needle 'xt'")
+	}
+	if !strings.Contains(p.items[0].label, "xtest") {
+		t.Fatalf("expected xtest at top of scored list, got %q", p.items[0].label)
+	}
+}
+
+// -- Phase 5: power-user accelerators --------------------------------
+
+func TestPaletteCtrlXOnSwitchKills(t *testing.T) {
+	c := makeFakeChild("a", "claude", KindAgent)
+	p := newPalette([]*Child{c}, "", "", preset.Set{})
+	// Cursor should already be on the switch row (it's the first
+	// selectable item with no Focused section).
+	idx, _ := findItem(p, "switch")
+	if idx < 0 {
+		t.Fatalf("no switch item in palette")
+	}
+	p.cursor = idx
+	action, done, _ := p.handleInput([]byte{0x18}, 0)
+	if !done {
+		t.Fatalf("Ctrl-X on switch row didn't close palette: action=%+v", action)
+	}
+	if action.kind != "kill" || action.childID != "a" {
+		t.Fatalf("Ctrl-X action = %+v, want kill of 'a'", action)
+	}
+}
+
+func TestPaletteCtrlXOnNonSwitchIsNoOp(t *testing.T) {
+	p := newPalette(nil, "", "", preset.Set{})
+	// Cursor parks on Quit or Spawn entries — neither is a switch row.
+	_, done, _ := p.handleInput([]byte{0x18}, 0)
+	if done {
+		t.Fatalf("Ctrl-X on non-switch closed palette")
+	}
+}
+
+func TestPaletteHelpToggle(t *testing.T) {
+	p := newTestPalette()
+	// `?` with empty query opens help.
+	_, done, _ := p.handleInput([]byte("?"), 0)
+	if done {
+		t.Fatalf("? closed palette")
+	}
+	if !p.showHelp {
+		t.Fatalf("? didn't open help")
+	}
+	// Next keystroke dismisses.
+	_, _, _ = p.handleInput([]byte("a"), 0)
+	if p.showHelp {
+		t.Fatalf("help still showing after dismissing keystroke")
+	}
+}
+
+func TestPaletteHelpDoesNotInterceptInQuery(t *testing.T) {
+	p := newTestPalette()
+	p.query = []rune("dev")
+	p.rebuild()
+	_, _, _ = p.handleInput([]byte("?"), 0)
+	if p.showHelp {
+		t.Fatalf("? with non-empty query incorrectly opened help")
+	}
+	if string(p.query) != "dev?" {
+		t.Fatalf("? with non-empty query failed to append: %q", string(p.query))
+	}
+}
+
+func TestPaletteHomeEndJumpsOverHeaders(t *testing.T) {
+	pr := []*preset.Preset{{Name: "a"}, {Name: "b"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	// End jumps to last selectable.
+	p.cursorEnd()
+	if p.items[p.cursor].action.kind == "header" {
+		t.Fatalf("End landed on header: %+v", p.items[p.cursor])
+	}
+	if p.items[p.cursor].action.kind != "quit" {
+		t.Fatalf("End on simple palette should park on Quit; got %+v", p.items[p.cursor])
+	}
+	// Home returns to first selectable.
+	p.cursorHome()
+	if p.items[p.cursor].action.kind == "header" {
+		t.Fatalf("Home landed on header: %+v", p.items[p.cursor])
+	}
+}
+
+func TestPaletteAltDigitQuickPick(t *testing.T) {
+	pr := []*preset.Preset{{Name: "first"}, {Name: "second"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	// Alt-1 picks the first selectable item (Spawn agent: first).
+	action, done, adv := p.handleInput([]byte("\x1b1"), 0)
+	if adv != 2 {
+		t.Fatalf("Alt-1 advance %d, want 2", adv)
+	}
+	if !done {
+		t.Fatalf("Alt-1 didn't close palette")
+	}
+	if action.kind != "spawn-agent" || action.preset == nil || action.preset.Name != "first" {
+		t.Fatalf("Alt-1 action = %+v, want spawn-agent first", action)
+	}
+}
+
+func TestAutoSummaryCadenceCyclesSoloValues(t *testing.T) {
+	p := newPalette(nil, "", "", preset.Set{}, defaultSettings())
+	p.mode = paletteModeAutoSummary
+	for i, row := range autoSummaryRows() {
+		if row.key == "cadence" {
+			p.cursor = i
+			break
+		}
+	}
+	if p.settings.AutoSummary.Cadence != "1m" {
+		t.Fatalf("initial cadence = %q", p.settings.AutoSummary.Cadence)
+	}
+	action, done, _ := p.activateAutoSummaryRow()
+	if done || action.kind != "settings-save" {
+		t.Fatalf("first cycle action = %+v done=%v, want settings-save without close", action, done)
+	}
+	if p.settings.AutoSummary.Cadence != "15s" {
+		t.Fatalf("first cycle cadence = %q", p.settings.AutoSummary.Cadence)
+	}
+	action, done, _ = p.activateAutoSummaryRow()
+	if done || action.kind != "settings-save" {
+		t.Fatalf("second cycle action = %+v done=%v, want settings-save without close", action, done)
+	}
+	if p.settings.AutoSummary.Cadence != "30s" {
+		t.Fatalf("second cycle cadence = %q", p.settings.AutoSummary.Cadence)
+	}
+	action, done, _ = p.activateAutoSummaryRow()
+	if done || action.kind != "settings-save" {
+		t.Fatalf("third cycle action = %+v done=%v, want settings-save without close", action, done)
+	}
+	if p.settings.AutoSummary.Cadence != "1m" {
+		t.Fatalf("third cycle cadence = %q", p.settings.AutoSummary.Cadence)
+	}
+}
+
+func TestAutoSummaryScreenOmitsExplicitSaveCancelBackRows(t *testing.T) {
+	omitted := map[string]bool{
+		"Save settings":    true,
+		"Cancel":           true,
+		"Back to Settings": true,
+	}
+	for _, row := range autoSummaryRows() {
+		if omitted[row.label] {
+			t.Fatalf("auto-summary settings should not show %q", row.label)
+		}
+	}
+}
+
+func TestAutoSummaryRenderOmitsStaleSettingsHelp(t *testing.T) {
+	p := newPalette(nil, "", "", preset.Set{}, defaultSettings())
+	p.mode = paletteModeAutoSummary
+	var b bytes.Buffer
+	p.renderAutoSummary(wrapWriter(&b), 100, 30)
+	out := b.String()
+	for _, text := range []string{
+		"Save settings",
+		"Cancel",
+		"Back to Settings",
+		"changes save",
+		"applies immediately",
+	} {
+		if strings.Contains(out, text) {
+			t.Fatalf("auto-summary render should not contain %q:\n%s", text, out)
+		}
+	}
+}
+
+func TestAutoSummaryValueRowsStyleLabelAndValueSeparately(t *testing.T) {
+	p := newPalette(nil, "", "", preset.Set{}, defaultSettings())
+	rows := p.autoSummaryDisplayRows()
+	for _, row := range rows {
+		if strings.Contains(row, "Cadence:") {
+			if !strings.HasPrefix(row, styleHint+"Cadence:"+styleReset+" ") {
+				t.Fatalf("cadence row styling = %q", row)
+			}
+			if strings.Contains(strings.TrimPrefix(row, styleHint+"Cadence:"+styleReset+" "), styleHint) {
+				t.Fatalf("cadence value should use regular text styling: %q", row)
+			}
+			return
+		}
+	}
+	t.Fatal("missing cadence display row")
+}
+
+func TestAutoSummaryTextInputSavesWhenSubmitted(t *testing.T) {
+	p := newPalette(nil, "", "", preset.Set{}, defaultSettings())
+	p.mode = paletteModeSettingsInput
+	p.settingsInput = &settingsInputForm{
+		title: "codex model",
+		field: "codex_model",
+		value: []rune("custom-model"),
+	}
+	action, done, _ := p.handleSettingsTextInput([]byte{'\r'}, 0)
+	if done || action.kind != "settings-save" {
+		t.Fatalf("submit action = %+v done=%v, want settings-save without close", action, done)
+	}
+	if got := p.settings.AutoSummary.modelFor("codex"); got != "custom-model" {
+		t.Fatalf("codex model = %q", got)
+	}
+}
+
+func TestPaletteFormCtrlRTogglesRelaunchFromCommandField(t *testing.T) {
+	p := newPalette(nil, "", "", preset.Set{})
+	p.mode = paletteModeSpawnForm
+	p.form = &spawnProcessForm{}
+	// Type without leaving the command field, then Ctrl-R.
+	for _, b := range []byte("xyz") {
+		_, _, _ = p.handleInput([]byte{b}, 0)
+	}
+	if p.form.field != 0 {
+		t.Fatalf("field jumped to %d", p.form.field)
+	}
+	_, _, _ = p.handleInput([]byte{0x12}, 0)
+	if !p.form.relaunch {
+		t.Fatalf("Ctrl-R didn't toggle relaunch from command field")
+	}
+	// Second press toggles back.
+	_, _, _ = p.handleInput([]byte{0x12}, 0)
+	if p.form.relaunch {
+		t.Fatalf("second Ctrl-R didn't toggle off")
+	}
+}
+
+// -- Phase 6: counter / scroll indicator -----------------------------
+
+func TestPaletteFooterCounter(t *testing.T) {
+	pr := []*preset.Preset{{Name: "a"}, {Name: "b"}, {Name: "c"}}
+	p := newPalette(nil, "", "", preset.Set{Agents: pr})
+	total := p.visibleSelectableCount()
+	if total < 4 { // 3 spawn-agents + terminal + custom + quit
+		t.Fatalf("expected ≥4 selectables; got %d", total)
+	}
+	idx := p.selectableIndex()
+	if idx <= 0 {
+		t.Fatalf("selectable index = %d on freshly-built palette; want ≥1", idx)
+	}
+}

internal/app/ring_test.go

@@ -90,6 +90,8 @@ func TestStripANSIBytesEquivalence(t *testing.T) {
 	cases := []string{
 		"hello world",
 		"\x1b[31mred\x1b[0m text",
+		"\x1b]0;title\x07after osc",
+		"\x1b]2;title\x1b\\after st",
 		"line1\nline2\r\nline3",
 		"bell\x07ish",
 		"weird \x1bA escape",
@@ -104,3 +106,44 @@ func TestStripANSIBytesEquivalence(t *testing.T) {
 		}
 	}
 }
+
+func TestNormalizeGridText(t *testing.T) {
+	cases := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "line endings",
+			in:   "one\r\ntwo\rthree",
+			want: "one\ntwo\nthree",
+		},
+		{
+			name: "trailing whitespace",
+			in:   "one   \ntwo\t\t\nthree",
+			want: "one\ntwo\nthree",
+		},
+		{
+			name: "collapse blank runs",
+			in:   "one\n\n\n two\n \n\t\nthree",
+			want: "one\n\n two\n\nthree",
+		},
+		{
+			name: "trim leading and trailing blanks",
+			in:   "\n \n\t\none\n\n",
+			want: "one",
+		},
+		{
+			name: "already clean",
+			in:   "one\n\ntwo\nthree",
+			want: "one\n\ntwo\nthree",
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := normalizeGridText(tc.in); got != tc.want {
+				t.Fatalf("normalizeGridText(%q) = %q, want %q", tc.in, got, tc.want)
+			}
+		})
+	}
+}

internal/app/scratchpad_delete_test.go

@@ -0,0 +1,137 @@
+package app
+
+import (
+	"errors"
+	"io"
+	"os"
+	"testing"
+
+	"github.com/hjbdev/patterm/internal/preset"
+	"github.com/hjbdev/patterm/internal/scratchpad"
+)
+
+func silenceStdout(t *testing.T) {
+	t.Helper()
+	old := os.Stdout
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("pipe stdout: %v", err)
+	}
+	done := make(chan struct{})
+	go func() {
+		_, _ = io.Copy(io.Discard, r)
+		close(done)
+	}()
+	os.Stdout = w
+	t.Cleanup(func() {
+		os.Stdout = old
+		_ = w.Close()
+		<-done
+		_ = r.Close()
+	})
+}
+
+func newScratchpadDeleteTestState(t *testing.T) (*uiState, *scratchpad.Store) {
+	t.Helper()
+	t.Setenv("XDG_DATA_HOME", t.TempDir())
+	pads, err := scratchpad.Open("scratchpad-delete-test")
+	if err != nil {
+		t.Fatalf("scratchpad.Open: %v", err)
+	}
+	sess := NewSession(t.TempDir(), "scratchpad-delete-test")
+	t.Cleanup(sess.Shutdown)
+	st := &uiState{
+		sess:       sess,
+		pads:       pads,
+		hostCols:   120,
+		hostRows:   40,
+		chromeWake: make(chan struct{}, 1),
+	}
+	return st, pads
+}
+
+func TestDeletingFocusedScratchpadFocusesAnotherPad(t *testing.T) {
+	silenceStdout(t)
+	st, pads := newScratchpadDeleteTestState(t)
+	if _, err := pads.Write("alpha.md", "alpha", ""); err != nil {
+		t.Fatalf("write alpha: %v", err)
+	}
+	if _, err := pads.Write("beta.md", "beta", ""); err != nil {
+		t.Fatalf("write beta: %v", err)
+	}
+	st.focusedPad = "alpha.md"
+	st.focusedName = "alpha.md"
+	st.padOffsetName = "alpha.md"
+	st.padOffset = 3
+
+	st.handlePadDelete("alpha.md")
+
+	if st.focusedPad != "beta.md" {
+		t.Fatalf("focusedPad = %q, want beta.md", st.focusedPad)
+	}
+	if st.focusedID != "" {
+		t.Fatalf("focusedID = %q, want empty while another pad is focused", st.focusedID)
+	}
+	if st.padOffset != 0 || st.padOffsetName != "beta.md" {
+		t.Fatalf("pad offset = (%q,%d), want (beta.md,0)", st.padOffsetName, st.padOffset)
+	}
+}
+
+func TestDeletingLastFocusedScratchpadFocusesRunningChild(t *testing.T) {
+	silenceStdout(t)
+	st, pads := newScratchpadDeleteTestState(t)
+	if _, err := pads.Write("only.md", "only", ""); err != nil {
+		t.Fatalf("write only: %v", err)
+	}
+	child := makeFakeChild("pid", "devserver", KindCommand)
+	addChild(st.sess, child)
+	st.focusedPad = "only.md"
+	st.focusedName = "only.md"
+
+	st.handlePadDelete("only.md")
+
+	if st.focusedPad != "" {
+		t.Fatalf("focusedPad = %q, want empty after falling back to child", st.focusedPad)
+	}
+	if st.focusedID != "pid" {
+		t.Fatalf("focusedID = %q, want pid", st.focusedID)
+	}
+}
+
+type scratchpadChangeRecorder struct {
+	count int
+}
+
+func (r *scratchpadChangeRecorder) scratchpadsChanged() {
+	r.count++
+}
+
+func TestToolHostScratchpadDeleteRemovesPadAndRefreshes(t *testing.T) {
+	t.Setenv("XDG_DATA_HOME", t.TempDir())
+	pads, err := scratchpad.Open("scratchpad-delete-host-test")
+	if err != nil {
+		t.Fatalf("scratchpad.Open: %v", err)
+	}
+	if _, err := pads.Write("doomed.md", "content", ""); err != nil {
+		t.Fatalf("write doomed.md: %v", err)
+	}
+	recorder := &scratchpadChangeRecorder{}
+	host := newToolHost(nil, pads, nil, preset.Set{}, nil, 120, 40)
+	host.scratch = recorder
+
+	if err := host.ScratchpadDelete("doomed.md"); err != nil {
+		t.Fatalf("ScratchpadDelete: %v", err)
+	}
+	if recorder.count != 1 {
+		t.Fatalf("scratchpadsChanged calls = %d, want 1", recorder.count)
+	}
+	if _, _, err := pads.Read("doomed.md"); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("read deleted pad error = %v, want os.ErrNotExist", err)
+	}
+	if err := host.ScratchpadDelete("doomed.md"); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("delete missing error = %v, want os.ErrNotExist", err)
+	}
+	if recorder.count != 1 {
+		t.Fatalf("scratchpadsChanged calls after failed delete = %d, want 1", recorder.count)
+	}
+}

internal/app/session.go

@@ -50,6 +50,11 @@ type Session struct {
 	// JSON file so they can be re-spawned after patterm restarts.
 	// Optional; nil means "no persistence" (used by unit tests).
 	persistStore *persist.Store
+
+	// metrics is the optional performance tracker. nil when --profile
+	// is off. The pump goroutine reads it via atomic Load so installing
+	// metrics post-construction doesn't race with running children.
+	metrics atomic.Pointer[metricsTracker]
 }
 
 // SetPersistStore attaches a process-persistence store. Future Spawn /
@@ -61,6 +66,18 @@ func (s *Session) SetPersistStore(p *persist.Store) {
 	s.mu.Unlock()
 }
 
+// SetMetrics installs the per-session performance tracker. Safe to
+// call with nil to disable (the default). Reads on the hot path go
+// through atomic.Pointer.Load() with no lock; SetMetrics swaps the
+// pointer once at startup.
+func (s *Session) SetMetrics(m *metricsTracker) {
+	s.metrics.Store(m)
+}
+
+func (s *Session) loadMetrics() *metricsTracker {
+	return s.metrics.Load()
+}
+
 // ChildEventListener is implemented by the TUI to react to lifecycle
 // events without polling.
 type ChildEventListener interface {
@@ -74,6 +91,12 @@ type ChildEventListener interface {
 	// updates a child's IdleState. Listeners use this to repaint the
 	// sidebar badge and to evaluate idle-aware timers.
 	OnChildStateChanged(childID string, state IdleState)
+	// OnChildClosed fires when a child is being removed from the
+	// session (either via close_process, or — for agent/terminal
+	// kinds — when the PTY exits and the entry will never be
+	// restarted). It signals that any pending references to childID
+	// (e.g. timers owned by or watching it) should be dropped.
+	OnChildClosed(childID string)
 }
 
 func NewSession(projectDir, projectKey string) *Session {
@@ -150,6 +173,12 @@ func (s *Session) emitStateChanged(id string, state IdleState) {
 	}
 }
 
+func (s *Session) emitClosed(id string) {
+	for _, l := range s.listenersSnapshot() {
+		l.OnChildClosed(id)
+	}
+}
+
 func (s *Session) ChildEnv() []string {
 	env := os.Environ()
 	// Mark patterm-owned PTYs so a recursive `patterm` invocation can
@@ -357,10 +386,29 @@ func (s *Session) Close(id string, sig syscall.Signal) error {
 		}
 	}
 	s.mu.Unlock()
+	// Notify listeners outside s.mu so they can take their own locks
+	// without inversion. Timer manager uses this to drop pending
+	// timers owned by or watching the closed child — otherwise the
+	// next classifier tick can deliver a stale fire to the parent.
+	s.emitClosed(id)
 	s.forgetPersisted(id)
 	return nil
 }
 
+// Terminate stops a live child with SIGTERM/SIGKILL escalation but
+// leaves its session entry intact so callers can keep showing the
+// exited pane.
+func (s *Session) Terminate(id string, sig syscall.Signal) error {
+	c := s.FindChild(id)
+	if c == nil {
+		return fmt.Errorf("no such process %q", id)
+	}
+	if c.IsLive() {
+		terminateAndWait(c, sig, childStopTimeout)
+	}
+	return nil
+}
+
 // mintUniqueIDLocked mints an opaque process_id (SPEC §7) and retries
 // if it collides with an existing entry. Caller holds s.mu.
 func (s *Session) mintUniqueIDLocked() string {
@@ -392,17 +440,37 @@ func (s *Session) pumpChild(c *Child, runID uint64) {
 			}
 			chunk := buf[:n]
 			if em := c.Emulator(); em != nil {
+				m := s.loadMetrics()
+				wstart := time.Time{}
+				if m != nil {
+					wstart = time.Now()
+				}
 				if _, werr := em.Write(chunk); werr != nil {
 					logf("emulator.Write(child %s): %v", c.ID, werr)
 				}
+				if m != nil {
+					m.recordEmuWrite(time.Since(wstart))
+				}
 				// OSC 0/2 title updates ride on the same byte stream as
 				// the rest of the output. Polling the emulator after each
-				// Write is cheap (one cgo call returning a borrowed
-				// string) and lets the classifier treat title changes as
-				// an activity signal — even when the title isn't visible
-				// in the rendered grid.
-				if t, terr := em.Title(); terr == nil {
-					c.recordTitle(t)
+				// chunk is cheap on its own (one CGO call) but codex/
+				// ratatui sends so many small chunks that the per-chunk
+				// CGO cost becomes measurable. Skip the Title poll when
+				// the chunk doesn't carry an OSC start byte at all; the
+				// title can only change on chunks that include one.
+				if containsOSC(chunk) {
+					tstart := time.Time{}
+					if m != nil {
+						tstart = time.Now()
+					}
+					if t, terr := em.Title(); terr == nil {
+						c.recordTitle(t)
+					}
+					if m != nil {
+						m.recordEmuTitle(time.Since(tstart), false)
+					}
+				} else if m != nil {
+					m.recordEmuTitle(0, true)
 				}
 			}
 			c.recordWrite(chunk)
@@ -449,6 +517,7 @@ func (s *Session) reapChild(c *Child, runID uint64) {
 			}
 		}
 		s.mu.Unlock()
+		s.emitClosed(c.ID)
 	}
 }
 
@@ -679,6 +748,24 @@ func (s *Session) Shutdown() {
 	}
 }
 
+// containsOSC reports whether chunk holds a sequence that could begin
+// an OSC. OSC starts as ESC ] (0x1b 0x5d) or the bare C1 ] (0x9d),
+// so a chunk without either cannot have changed the emulator's OSC
+// title state. Used to short-circuit the per-chunk Title() poll from
+// pumpChild, which otherwise pays a CGO call for every chunk even
+// when codex/ratatui is just emitting SGR-styled output.
+func containsOSC(chunk []byte) bool {
+	for i, b := range chunk {
+		if b == 0x9d {
+			return true
+		}
+		if b == 0x1b && i+1 < len(chunk) && chunk[i+1] == ']' {
+			return true
+		}
+	}
+	return false
+}
+
 func logf(format string, args ...any) {
 	if os.Getenv("PATTERM_DEBUG_LOG") == "" {
 		return

internal/app/session_test.go

@@ -1,6 +1,7 @@
 package app
 
 import (
+	"strings"
 	"syscall"
 	"testing"
 	"time"
@@ -101,6 +102,50 @@ func TestSpawnInstallsIdleDetectionBeforePublish(t *testing.T) {
 	}
 }
 
+func TestTerminateEscalatesWithoutRemovingEntry(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	c, err := sess.Spawn(SpawnSpec{
+		Kind: KindAgent,
+		Argv: []string{"sh", "-c", "trap '' TERM; echo ready; while :; do sleep 1; done"},
+	}, 80, 24)
+	if err != nil {
+		t.Fatalf("spawn: %v", err)
+	}
+	t.Cleanup(func() {
+		if c.IsLive() {
+			_ = c.signal(syscall.SIGKILL)
+		}
+	})
+	waitUntilLive(t, c)
+	waitForStreamText(t, c, "ready")
+
+	start := time.Now()
+	if err := sess.Terminate(c.ID, syscall.SIGTERM); err != nil {
+		t.Fatalf("Terminate: %v", err)
+	}
+	if elapsed := time.Since(start); elapsed < childStopTimeout {
+		t.Fatalf("Terminate returned before SIGKILL fallback: elapsed=%s timeout=%s", elapsed, childStopTimeout)
+	}
+	waitUntilNotLive(t, c)
+
+	if got := sess.FindChild(c.ID); got == nil {
+		t.Fatalf("Terminate removed child entry %s", c.ID)
+	}
+}
+
+func waitForStreamText(t *testing.T, c *Child, want string) {
+	t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		b, _ := c.StreamRead(0)
+		if strings.Contains(string(b), want) {
+			return
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	t.Fatalf("child %s never wrote %q", c.ID, want)
+}
+
 func waitUntilLive(t *testing.T, c *Child) {
 	t.Helper()
 	deadline := time.Now().Add(5 * time.Second)

internal/app/settings.go

@@ -0,0 +1,150 @@
+package app
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/hjbdev/patterm/internal/preset"
+)
+
+const (
+	defaultSummaryProvider = "codex"
+	defaultCodexModel      = "gpt-5.4-mini"
+	defaultOpenCodeModel   = "opencode-go/minimax-m2.7"
+	defaultClaudeModel     = "claude-haiku-4-5"
+)
+
+type settings struct {
+	AutoSummary autoSummarySettings `json:"auto_summary"`
+}
+
+type autoSummarySettings struct {
+	Enabled         bool              `json:"enabled"`
+	Provider        string            `json:"provider"`
+	Models          map[string]string `json:"models"`
+	Cadence         string            `json:"cadence"`
+	QuietWindowMS   int               `json:"quiet_window_ms"`
+	MinInputChars   int               `json:"min_input_chars"`
+	MaxHistoryChars int               `json:"max_history_chars"`
+}
+
+func defaultSettings() settings {
+	return settings{
+		AutoSummary: autoSummarySettings{
+			Enabled:         true,
+			Provider:        defaultSummaryProvider,
+			Models:          defaultSummaryModels(),
+			Cadence:         "1m",
+			QuietWindowMS:   3000,
+			MinInputChars:   4,
+			MaxHistoryChars: 12000,
+		},
+	}
+}
+
+func defaultSummaryModels() map[string]string {
+	return map[string]string{
+		"codex":    defaultCodexModel,
+		"opencode": defaultOpenCodeModel,
+		"claude":   defaultClaudeModel,
+	}
+}
+
+func loadSettings() (settings, string, error) {
+	base, err := preset.ConfigDir()
+	if err != nil {
+		return settings{}, "", err
+	}
+	path := filepath.Join(base, "settings.json")
+	st := defaultSettings()
+	b, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return st, path, nil
+		}
+		return st, path, fmt.Errorf("settings: read %s: %w", path, err)
+	}
+	if err := json.Unmarshal(b, &st); err != nil {
+		return defaultSettings(), path, fmt.Errorf("settings: parse %s: %w", path, err)
+	}
+	st.normalize()
+	return st, path, nil
+}
+
+func saveSettings(path string, st settings) error {
+	if path == "" {
+		return fmt.Errorf("settings: empty path")
+	}
+	st.normalize()
+	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+		return err
+	}
+	b, err := json.MarshalIndent(st, "", "  ")
+	if err != nil {
+		return err
+	}
+	b = append(b, '\n')
+	return os.WriteFile(path, b, 0o600)
+}
+
+func (st *settings) normalize() {
+	def := defaultSettings()
+	if st.AutoSummary.Provider == "" {
+		st.AutoSummary.Provider = def.AutoSummary.Provider
+	}
+	switch st.AutoSummary.Provider {
+	case "codex", "opencode", "claude":
+	default:
+		st.AutoSummary.Provider = def.AutoSummary.Provider
+	}
+	if st.AutoSummary.Models == nil {
+		st.AutoSummary.Models = defaultSummaryModels()
+	} else {
+		for k, v := range defaultSummaryModels() {
+			if st.AutoSummary.Models[k] == "" {
+				st.AutoSummary.Models[k] = v
+			}
+		}
+	}
+	if st.AutoSummary.Cadence == "" {
+		st.AutoSummary.Cadence = def.AutoSummary.Cadence
+	}
+	if st.AutoSummary.QuietWindowMS <= 0 {
+		st.AutoSummary.QuietWindowMS = def.AutoSummary.QuietWindowMS
+	}
+	if st.AutoSummary.MinInputChars <= 0 {
+		st.AutoSummary.MinInputChars = def.AutoSummary.MinInputChars
+	}
+	if st.AutoSummary.MaxHistoryChars <= 0 {
+		st.AutoSummary.MaxHistoryChars = def.AutoSummary.MaxHistoryChars
+	}
+}
+
+func (st settings) clone() settings {
+	st.normalize()
+	if st.AutoSummary.Models != nil {
+		models := make(map[string]string, len(st.AutoSummary.Models))
+		for k, v := range st.AutoSummary.Models {
+			models[k] = v
+		}
+		st.AutoSummary.Models = models
+	}
+	return st
+}
+
+func (a autoSummarySettings) clone() autoSummarySettings {
+	st := settings{AutoSummary: a}.clone()
+	return st.AutoSummary
+}
+
+func (a autoSummarySettings) modelFor(provider string) string {
+	if a.Models == nil {
+		return defaultSummaryModels()[provider]
+	}
+	if m := a.Models[provider]; m != "" {
+		return m
+	}
+	return defaultSummaryModels()[provider]
+}

internal/app/settings_test.go

@@ -0,0 +1,72 @@
+package app
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoadSettingsDefaults(t *testing.T) {
+	t.Setenv("XDG_CONFIG_HOME", t.TempDir())
+	st, path, err := loadSettings()
+	if err != nil {
+		t.Fatalf("loadSettings: %v", err)
+	}
+	if filepath.Base(path) != "settings.json" {
+		t.Fatalf("settings path = %q", path)
+	}
+	if !st.AutoSummary.Enabled {
+		t.Fatal("auto-summary should default enabled")
+	}
+	if st.AutoSummary.Provider != "codex" {
+		t.Fatalf("provider = %q want codex", st.AutoSummary.Provider)
+	}
+	if st.AutoSummary.Cadence != "1m" {
+		t.Fatalf("cadence = %q want 1m", st.AutoSummary.Cadence)
+	}
+	if got := st.AutoSummary.modelFor("codex"); got != "gpt-5.4-mini" {
+		t.Fatalf("codex model = %q", got)
+	}
+	if got := st.AutoSummary.modelFor("opencode"); got != "opencode-go/minimax-m2.7" {
+		t.Fatalf("opencode model = %q", got)
+	}
+}
+
+func TestSettingsCloneDoesNotShareModelMap(t *testing.T) {
+	st := defaultSettings()
+	cp := st.clone()
+	cp.AutoSummary.Models["codex"] = "changed"
+	if st.AutoSummary.Models["codex"] == "changed" {
+		t.Fatal("clone shared Models map with original")
+	}
+	a := st.AutoSummary.clone()
+	a.Models["opencode"] = "changed"
+	if st.AutoSummary.Models["opencode"] == "changed" {
+		t.Fatal("autoSummarySettings clone shared Models map with original")
+	}
+}
+
+func TestSaveAndLoadSettings(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", dir)
+	st := defaultSettings()
+	st.AutoSummary.Provider = "opencode"
+	st.AutoSummary.Models["opencode"] = "minimax/test"
+	path := filepath.Join(dir, "patterm", "settings.json")
+	if err := saveSettings(path, st); err != nil {
+		t.Fatalf("saveSettings: %v", err)
+	}
+	if _, err := os.Stat(path); err != nil {
+		t.Fatalf("settings file missing: %v", err)
+	}
+	got, _, err := loadSettings()
+	if err != nil {
+		t.Fatalf("loadSettings: %v", err)
+	}
+	if got.AutoSummary.Provider != "opencode" {
+		t.Fatalf("provider = %q", got.AutoSummary.Provider)
+	}
+	if got.AutoSummary.modelFor("opencode") != "minimax/test" {
+		t.Fatalf("opencode model = %q", got.AutoSummary.modelFor("opencode"))
+	}
+}

internal/app/sidebar.go

@@ -12,6 +12,128 @@ const (
 	statusRows  = 1
 )
 
+// fitName returns name truncated to fit budget visible cells, with a
+// trailing "…" when it overflows. Operates on RAW (unstyled) input;
+// the caller wraps the result in SGR. Returns "" when budget <= 0.
+func fitName(name string, budget int) string {
+	if budget <= 0 {
+		return ""
+	}
+	runes := []rune(name)
+	if len(runes) <= budget {
+		return name
+	}
+	if budget == 1 {
+		return "…"
+	}
+	return string(runes[:budget-1]) + "…"
+}
+
+// marqueeWindow returns the window of name starting at offset, exactly
+// budget cells wide. Pre: caller has decided the name overflows budget
+// and offset is in [0, len([]rune(name))-budget]. Operates on RAW
+// (unstyled) input.
+func marqueeWindow(name string, budget, offset int) string {
+	if budget <= 0 {
+		return ""
+	}
+	runes := []rune(name)
+	if len(runes) <= budget {
+		return name
+	}
+	if offset < 0 {
+		offset = 0
+	}
+	end := offset + budget
+	if end > len(runes) {
+		end = len(runes)
+		offset = end - budget
+		if offset < 0 {
+			offset = 0
+		}
+	}
+	return string(runes[offset:end])
+}
+
+// clampVisible truncates s so that its visible (non-SGR) length is at
+// most width cells, preserving any active style by appending a reset.
+// Used as a defensive net by write() so a row whose decoration was
+// mis-sized still cannot spill past the sidebar band into the PTY area.
+func clampVisible(s string, width int) string {
+	if width <= 0 {
+		return ""
+	}
+	if visibleLen(s) <= width {
+		return s
+	}
+	var b strings.Builder
+	b.Grow(len(s))
+	visible := 0
+	inEsc := false
+	for _, r := range s {
+		if inEsc {
+			b.WriteRune(r)
+			if r == 'm' || r == 'H' {
+				inEsc = false
+			}
+			continue
+		}
+		if r == 0x1b {
+			inEsc = true
+			b.WriteRune(r)
+			continue
+		}
+		if visible >= width {
+			break
+		}
+		b.WriteRune(r)
+		visible++
+	}
+	b.WriteString(styleReset)
+	return b.String()
+}
+
+// chooseSidebarSuffix decides whether to keep or drop the trailing
+// timer indicator from a sidebar row's suffix. When the row's name
+// would have to ellipsise with the timer present, but the budget
+// freed by dropping the timer still leaves at least 6 cells for the
+// name, the timer is dropped. The name is the only identifier the
+// user has for that row; the timer is recoverable from the status
+// line and palette.
+func chooseSidebarSuffix(nameRuneLen, width int, prefix, suffix, timer string) (string, int) {
+	prefixCost := visibleLen(prefix)
+	budget := width - prefixCost - visibleLen(suffix)
+	if nameRuneLen <= budget || timer == "" {
+		return suffix, budget
+	}
+	slim := strings.TrimSuffix(suffix, timer)
+	if slim == suffix {
+		return suffix, budget
+	}
+	slimBudget := width - prefixCost - visibleLen(slim)
+	if slimBudget >= 6 {
+		return slim, slimBudget
+	}
+	return suffix, budget
+}
+
+// rowNameSlot returns the unstyled name cell for a sidebar row.
+// Unfocused (or focused-and-fitting) rows get fitName with a trailing
+// "…" on overflow. The focused row, when its name overflows the
+// budget, gets the current marquee window — exactly budget cells
+// wide so the surrounding row geometry stays put while it animates.
+func (st *uiState) rowNameSlot(id, rawName string, budget int, focused bool) string {
+	if budget <= 0 {
+		return ""
+	}
+	runes := []rune(rawName)
+	if !focused || len(runes) <= budget {
+		return fitName(rawName, budget)
+	}
+	off, _, _ := st.marquee.step(id, len(runes), budget, time.Now())
+	return marqueeWindow(rawName, budget, off)
+}
+
 // formatShortDuration renders a duration as a short, sidebar-friendly
 // suffix: ms under 1s, "12s" under 60s, "3m" otherwise.
 func formatShortDuration(d time.Duration) string {
@@ -38,6 +160,10 @@ func formatShortDuration(d time.Duration) string {
 // computed main viewport, so the sidebar region is outside the child's
 // cursor range. We can redraw freely without fighting the child for cells.
 func (st *uiState) drawSidebar() {
+	var entry time.Time
+	if st.metrics != nil {
+		entry = time.Now()
+	}
 	st.mu.Lock()
 	palOpen := st.palette != nil
 	focus := st.focusedID
@@ -69,6 +195,9 @@ func (st *uiState) drawSidebar() {
 		if row > maxRow {
 			return
 		}
+		if visibleLen(content) > width {
+			content = clampVisible(content, width)
+		}
 		pad := width - visibleLen(content)
 		if pad < 0 {
 			pad = 0
@@ -150,14 +279,19 @@ func (st *uiState) drawSidebar() {
 		if c.AutoRestart() {
 			marker = " " + styleDim + "⟳" + styleReset
 		}
-		var line string
+		timer := timerIndicator(c)
+		var prefix, openStyle string
 		if focused {
-			line = " " + styleAccent + "▎" + styleReset + " " + glyph + " " +
-				styleBold + c.DisplayName() + styleReset + marker + timerIndicator(c)
+			prefix = " " + styleAccent + "▎" + styleReset + " " + glyph + " "
+			openStyle = styleBold
 		} else {
-			line = "   " + glyph + " " + styleHint + c.DisplayName() + styleReset + marker + timerIndicator(c)
+			prefix = "   " + glyph + " "
+			openStyle = styleHint
 		}
-		write(line)
+		raw := c.DisplayName()
+		suffix, budget := chooseSidebarSuffix(len([]rune(raw)), width, prefix, marker+timer, timer)
+		nameCell := st.rowNameSlot(c.ID, raw, budget, focused)
+		write(prefix + openStyle + nameCell + styleReset + suffix)
 	}
 
 	// Agent Tree section — formerly "Session tree". Shows the active
@@ -182,14 +316,29 @@ func (st *uiState) drawSidebar() {
 		}
 		focused := c.ID == focus
 		glyph := statusGlyph(c, focused)
-		var line string
+		timer := timerIndicator(c)
+		var prefix, openStyle string
 		if focused {
-			line = " " + styleAccent + "▎" + styleReset + " " + indent + glyph + " " +
-				styleBold + c.DisplayName() + styleReset + timerIndicator(c)
+			prefix = " " + styleAccent + "▎" + styleReset + " " + indent + glyph + " "
+			openStyle = styleBold
 		} else {
-			line = "   " + indent + glyph + " " + styleHint + c.DisplayName() + styleReset + timerIndicator(c)
+			prefix = "   " + indent + glyph + " "
+			openStyle = styleHint
+		}
+		raw := c.DisplayName()
+		suffix, budget := chooseSidebarSuffix(len([]rune(raw)), width, prefix, timer, timer)
+		nameCell := st.rowNameSlot(c.ID, raw, budget, focused)
+		write(prefix + openStyle + nameCell + styleReset + suffix)
+	}
+
+	if summary := st.activeSummaryRaw(); summary != "" && row+2 <= maxRow {
+		write("")
+		for _, line := range wrapSidebarSummary(summary, width-4) {
+			if row > maxRow {
+				break
+			}
+			write("   " + styleDim + line + styleReset)
 		}
-		write(line)
 	}
 
 	// Scratchpads list — names only. The preview pane used to live
@@ -208,14 +357,18 @@ func (st *uiState) drawSidebar() {
 					if row > maxRow {
 						break
 					}
-					var line string
-					if e.Name == focusPad {
-						line = " " + styleAccent + "▎" + styleReset + " " +
-							styleBold + e.Name + styleReset
+					focused := e.Name == focusPad
+					var prefix, openStyle string
+					if focused {
+						prefix = " " + styleAccent + "▎" + styleReset + " "
+						openStyle = styleBold
 					} else {
-						line = "   " + styleHint + e.Name + styleReset
+						prefix = "   "
+						openStyle = styleHint
 					}
-					write(line)
+					budget := width - visibleLen(prefix)
+					nameCell := st.rowNameSlot("pad:"+e.Name, e.Name, budget, focused)
+					write(prefix + openStyle + nameCell + styleReset)
 				}
 			}
 		}
@@ -231,13 +384,64 @@ func (st *uiState) drawSidebar() {
 	st.chromeCacheMu.Lock()
 	if frame == st.sidebarCache {
 		st.chromeCacheMu.Unlock()
+		if st.metrics != nil {
+			st.metrics.recordSidebar(time.Since(entry), true)
+		}
 		return
 	}
 	st.sidebarCache = frame
 	st.chromeCacheMu.Unlock()
+	if st.metrics != nil {
+		defer func() { st.metrics.recordSidebar(time.Since(entry), false) }()
+	}
 
 	st.outMu.Lock()
 	// Save cursor; emit the sidebar; restore.
 	fmt.Fprintf(os.Stdout, "\x1b7%s\x1b8", frame)
 	st.outMu.Unlock()
 }
+
+func wrapSidebarSummary(s string, width int) []string {
+	if width < 1 {
+		width = 1
+	}
+	words := strings.Fields(s)
+	if len(words) == 0 {
+		return nil
+	}
+	var out []string
+	var cur string
+	for _, word := range words {
+		if visibleLen(word) > width {
+			if cur != "" {
+				out = append(out, cur)
+				cur = ""
+			}
+			for visibleLen(word) > width {
+				out = append(out, clipRunes(word, width))
+				word = string([]rune(word)[width:])
+			}
+			if word != "" {
+				cur = word
+			}
+			continue
+		}
+		if cur == "" {
+			cur = word
+			continue
+		}
+		if visibleLen(cur)+1+visibleLen(word) <= width {
+			cur += " " + word
+			continue
+		}
+		out = append(out, cur)
+		cur = word
+	}
+	if cur != "" {
+		out = append(out, cur)
+	}
+	if len(out) > 3 {
+		out = out[:3]
+	}
+	return out
+}

internal/app/spawn_focus_test.go

@@ -0,0 +1,46 @@
+package app
+
+import (
+	"testing"
+)
+
+// TestOnChildSpawnedAgentChildKeepsFocus verifies that when a child is
+// spawned with a ParentID set (i.e. a patterm-managed agent caused the
+// spawn over MCP), OnChildSpawned does NOT steal viewport focus from
+// the currently focused child.
+func TestOnChildSpawnedAgentChildKeepsFocus(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	st := &uiState{sess: sess}
+
+	parent := newChildEntry("p_parent", "parent", KindAgent, nil, nil, "", "", "")
+	st.focusedID = parent.ID
+	st.focusedName = parent.Name
+
+	subAgent := newChildEntry("p_sub", "sub", KindAgent, nil, nil, parent.ID, "", "")
+
+	st.OnChildSpawned(subAgent)
+
+	if got := st.focusedID; got != parent.ID {
+		t.Fatalf("agent-initiated spawn should not change focusedID: want %q, got %q", parent.ID, got)
+	}
+	if got := st.focusedName; got != parent.Name {
+		t.Fatalf("focusedName changed: want %q, got %q", parent.Name, got)
+	}
+}
+
+// TestOnChildSpawnedPaletteChildTakesFocus verifies the legacy path is
+// preserved: spawns with an empty ParentID (palette, restore, external
+// MCP caller) still auto-focus the new child.
+func TestOnChildSpawnedPaletteChildTakesFocus(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	st := &uiState{sess: sess}
+	st.lastExit.Store(-1)
+
+	c := newChildEntry("p_new", "newchild", KindAgent, nil, nil, "", "", "")
+
+	st.OnChildSpawned(c)
+
+	if got := st.focusedID; got != c.ID {
+		t.Fatalf("palette-initiated spawn should auto-focus: want %q, got %q", c.ID, got)
+	}
+}

internal/app/summarizer.go

@@ -0,0 +1,463 @@
+package app
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+	"unicode"
+
+	"github.com/hjbdev/patterm/internal/preset"
+)
+
+const (
+	summaryTickInterval = time.Second
+	summaryTimeout      = 90 * time.Second
+	summaryMaxLineCells = 240
+)
+
+type summaryState struct {
+	Text      string
+	State     IdleState
+	UpdatedAt time.Time
+	Error     string
+}
+
+type summaryManager struct {
+	sess       *Session
+	projectDir string
+	presets    preset.Set
+	settings   func() autoSummarySettings
+	onUpdate   func()
+	onResult   func(string, summaryState)
+
+	mu      sync.Mutex
+	tracked map[string]bool
+	entries map[string]*summaryEntry
+}
+
+type summaryEntry struct {
+	armed          bool
+	dirty          bool
+	running        bool
+	lastInputAt    time.Time
+	lastOutputAt   time.Time
+	lastAttemptAt  time.Time
+	lastSummarized int64
+	state          summaryState
+}
+
+type summarizerResponse struct {
+	Summary string `json:"summary"`
+	State   string `json:"state"`
+}
+
+func newSummaryManager(sess *Session, projectDir string, presets preset.Set, settingsFn func() autoSummarySettings, onUpdate func(), onResult func(string, summaryState)) *summaryManager {
+	return &summaryManager{
+		sess:       sess,
+		projectDir: projectDir,
+		presets:    presets,
+		settings:   settingsFn,
+		onUpdate:   onUpdate,
+		onResult:   onResult,
+		tracked:    make(map[string]bool),
+		entries:    make(map[string]*summaryEntry),
+	}
+}
+
+func (m *summaryManager) run(ctx context.Context) {
+	ticker := time.NewTicker(summaryTickInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			m.maybeStart(ctx, time.Now())
+		}
+	}
+}
+
+func (m *summaryManager) ObserveHumanInput(childID string, b []byte) {
+	if m == nil || !m.isTracked(childID) {
+		return
+	}
+	cfg := m.settings()
+	if len(strings.TrimSpace(string(b))) < cfg.MinInputChars {
+		return
+	}
+	m.mu.Lock()
+	e := m.entryLocked(childID)
+	e.armed = true
+	e.lastInputAt = time.Now()
+	m.mu.Unlock()
+}
+
+func (m *summaryManager) ObserveOutput(childID string) {
+	if m == nil || !m.isTracked(childID) {
+		return
+	}
+	m.mu.Lock()
+	e := m.entryLocked(childID)
+	if e.armed {
+		e.dirty = true
+		e.lastOutputAt = time.Now()
+	}
+	m.mu.Unlock()
+}
+
+func (m *summaryManager) RegisterChild(c *Child) {
+	if m == nil || c == nil {
+		return
+	}
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if isTopLevelSummarizedAgent(c) {
+		m.tracked[c.ID] = true
+	} else {
+		delete(m.tracked, c.ID)
+	}
+}
+
+func (m *summaryManager) UnregisterChild(id string) {
+	if m == nil || id == "" {
+		return
+	}
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	delete(m.tracked, id)
+}
+
+func (m *summaryManager) isTracked(id string) bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.tracked[id]
+}
+
+func (m *summaryManager) Summary(childID string) summaryState {
+	if m == nil || childID == "" {
+		return summaryState{}
+	}
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if e := m.entries[childID]; e != nil {
+		return e.state
+	}
+	return summaryState{}
+}
+
+func (m *summaryManager) RunNow(ctx context.Context, childID string) {
+	if m == nil || childID == "" {
+		return
+	}
+	c := m.sess.FindChild(childID)
+	if !isTopLevelSummarizedAgent(c) {
+		return
+	}
+	m.mu.Lock()
+	e := m.entryLocked(c.ID)
+	if e.running {
+		m.mu.Unlock()
+		return
+	}
+	e.running = true
+	e.lastAttemptAt = time.Now()
+	m.mu.Unlock()
+	go m.runOne(ctx, c.ID, true)
+}
+
+func (m *summaryManager) Test(ctx context.Context) error {
+	cfg := m.settings()
+	return runSummarizerHealth(ctx, cfg, m.projectDir)
+}
+
+func (m *summaryManager) entryLocked(id string) *summaryEntry {
+	e := m.entries[id]
+	if e == nil {
+		e = &summaryEntry{}
+		m.entries[id] = e
+	}
+	return e
+}
+
+func (m *summaryManager) maybeStart(ctx context.Context, now time.Time) {
+	cfg := m.settings()
+	if !cfg.Enabled {
+		return
+	}
+	cadence, err := time.ParseDuration(cfg.Cadence)
+	if err != nil || cadence <= 0 {
+		cadence = time.Minute
+	}
+	quiet := time.Duration(cfg.QuietWindowMS) * time.Millisecond
+	var startID string
+	for _, c := range m.sess.Children() {
+		if !isTopLevelSummarizedAgent(c) {
+			continue
+		}
+		m.mu.Lock()
+		e := m.entryLocked(c.ID)
+		eligible := e.armed && e.dirty && !e.running &&
+			!e.lastOutputAt.IsZero() && now.Sub(e.lastOutputAt) >= quiet &&
+			(e.lastAttemptAt.IsZero() || now.Sub(e.lastAttemptAt) >= cadence) &&
+			c.ScreenVersion() != e.lastSummarized
+		if eligible {
+			e.running = true
+			e.lastAttemptAt = now
+			startID = c.ID
+		}
+		m.mu.Unlock()
+		if startID != "" {
+			go m.runOne(ctx, startID, false)
+			return
+		}
+	}
+}
+
+func (m *summaryManager) runOne(ctx context.Context, childID string, manual bool) {
+	c := m.sess.FindChild(childID)
+	if c == nil {
+		m.finish(childID, summaryState{Error: "process disappeared"}, 0)
+		return
+	}
+	cfg := m.settings()
+	snapshot := buildSummarySnapshot(c, cfg.MaxHistoryChars, m.chromeHintsFor(c.PresetRef))
+	if strings.TrimSpace(snapshot) == "" {
+		m.finish(childID, summaryState{Error: "empty snapshot"}, c.ScreenVersion())
+		return
+	}
+	runCtx, cancel := context.WithTimeout(ctx, summaryTimeout)
+	defer cancel()
+	resp, err := runSummarizer(runCtx, cfg, m.projectDir, snapshot)
+	st := summaryState{UpdatedAt: time.Now()}
+	if err != nil {
+		st.Error = err.Error()
+		m.finish(childID, st, c.ScreenVersion())
+		return
+	}
+	st.Text = strings.TrimSpace(resp.Summary)
+	st.State = summaryIdleState(resp.State)
+	if st.Text == "" {
+		st.Error = "empty summary"
+	}
+	if manual && st.Text != "" && st.State == StateUnknown {
+		st.State = c.IdleState()
+	}
+	m.finish(childID, st, c.ScreenVersion())
+}
+
+func (m *summaryManager) finish(childID string, st summaryState, version int64) {
+	m.mu.Lock()
+	e := m.entryLocked(childID)
+	e.running = false
+	if st.Text != "" || st.Error != "" {
+		if st.Text == "" && e.state.Text != "" {
+			st.Text = e.state.Text
+			st.State = e.state.State
+			st.UpdatedAt = e.state.UpdatedAt
+		}
+		e.state = st
+	}
+	if st.Text != "" {
+		e.armed = false
+		e.dirty = false
+		e.lastSummarized = version
+	}
+	m.mu.Unlock()
+	if m.onUpdate != nil {
+		m.onUpdate()
+	}
+	if m.onResult != nil && (st.Text != "" || st.Error != "") {
+		m.onResult(childID, st)
+	}
+}
+
+func isTopLevelSummarizedAgent(c *Child) bool {
+	return c != nil && c.Kind == KindAgent && c.ParentID == "" && c.Status() == StatusRunning
+}
+
+func (m *summaryManager) chromeHintsFor(presetName string) []string {
+	if presetName == "" {
+		return nil
+	}
+	for _, p := range m.presets.Agents {
+		if p.Name == presetName {
+			return p.ChromeTrimHints
+		}
+	}
+	return nil
+}
+
+func buildSummarySnapshot(c *Child, maxChars int, chromeHints []string) string {
+	if maxChars <= 0 {
+		maxChars = 12000
+	}
+	grid := ""
+	if em := c.Emulator(); em != nil {
+		if txt, err := em.PlainText(); err == nil {
+			grid = compactSummaryText(applyChromeTrim(txt, chromeHints))
+		}
+	}
+	tailBytes := max(maxChars*4, maxChars)
+	b := c.tailBytes(tailBytes)
+	history := compactSummaryText(applyChromeTrim(string(stripANSIBytes(nil, b)), chromeHints))
+	history = tailString(history, maxChars)
+	var out strings.Builder
+	if history != "" {
+		out.WriteString("Recent rendered history:\n")
+		out.WriteString(history)
+		out.WriteString("\n\n")
+	}
+	if grid != "" && !strings.Contains(history, grid) {
+		out.WriteString("Current visible grid:\n")
+		out.WriteString(grid)
+	}
+	return tailString(out.String(), maxChars)
+}
+
+func compactSummaryText(in string) string {
+	in = string(stripANSIBytes(nil, []byte(in)))
+	in = strings.ReplaceAll(in, "\r\n", "\n")
+	in = strings.ReplaceAll(in, "\r", "\n")
+	lines := strings.Split(in, "\n")
+	out := make([]string, 0, len(lines))
+	blank := false
+	for _, line := range lines {
+		line = strings.TrimRightFunc(line, unicode.IsSpace)
+		line = strings.Map(func(r rune) rune {
+			if r == '\t' || r == '\n' {
+				return r
+			}
+			if r < 0x20 || r == 0x7f {
+				return -1
+			}
+			return r
+		}, line)
+		line = truncateSummaryLine(line, summaryMaxLineCells)
+		if strings.TrimSpace(line) == "" {
+			if blank {
+				continue
+			}
+			blank = true
+			out = append(out, "")
+			continue
+		}
+		blank = false
+		out = append(out, line)
+	}
+	return strings.TrimSpace(strings.Join(out, "\n"))
+}
+
+func truncateSummaryLine(s string, max int) string {
+	if max <= 0 || visibleLen(s) <= max {
+		return s
+	}
+	return clipRunes(s, max-1) + "…"
+}
+
+func tailString(s string, max int) string {
+	rs := []rune(s)
+	if len(rs) <= max {
+		return s
+	}
+	return string(rs[len(rs)-max:])
+}
+
+func runSummarizer(ctx context.Context, cfg autoSummarySettings, projectDir, snapshot string) (summarizerResponse, error) {
+	prompt := summaryPrompt(snapshot)
+	out, err := runSummarizerCommand(ctx, cfg, projectDir, prompt)
+	if err != nil {
+		return summarizerResponse{}, err
+	}
+	resp, err := parseSummarizerResponse(out)
+	if err != nil {
+		return summarizerResponse{}, err
+	}
+	if summaryIdleState(resp.State) == StateUnknown {
+		return summarizerResponse{}, fmt.Errorf("invalid summary state %q", resp.State)
+	}
+	return resp, nil
+}
+
+func runSummarizerHealth(ctx context.Context, cfg autoSummarySettings, projectDir string) error {
+	out, err := runSummarizerCommand(ctx, cfg, projectDir, "Reply with exactly: patterm okay")
+	if err != nil {
+		return err
+	}
+	if strings.TrimSpace(out) != "patterm okay" {
+		return fmt.Errorf("health check did not return patterm okay")
+	}
+	return nil
+}
+
+func runSummarizerCommand(ctx context.Context, cfg autoSummarySettings, projectDir, prompt string) (string, error) {
+	provider := cfg.Provider
+	model := cfg.modelFor(provider)
+	var cmd *exec.Cmd
+	switch provider {
+	case "opencode":
+		cmd = exec.CommandContext(ctx, "opencode", "run", "--model", model, "--dir", projectDir, prompt)
+	case "claude":
+		cmd = exec.CommandContext(ctx, "claude", "--print", "--model", model, prompt)
+	default:
+		cmd = exec.CommandContext(ctx, "codex", "exec", "--ephemeral", "--skip-git-repo-check", "--sandbox", "read-only", "--model", model, "-")
+		cmd.Stdin = strings.NewReader(prompt)
+	}
+	cmd.Dir = projectDir
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	out, err := cmd.Output()
+	if err != nil {
+		msg := strings.TrimSpace(stderr.String())
+		if msg == "" {
+			msg = err.Error()
+		}
+		return "", fmt.Errorf("%s summarizer: %s", provider, msg)
+	}
+	return string(out), nil
+}
+
+func summaryPrompt(snapshot string) string {
+	return "Summarize this terminal/agent snapshot for a compact UI catch-up aid.\n" +
+		"Return only JSON with keys summary and state. State must be one of IDLE, PERMISSION, THINKING, WORKING, ERROR.\n" +
+		"Keep summary under 180 characters, concrete, and avoid mentioning that you are summarizing.\n\n" +
+		snapshot
+}
+
+func parseSummarizerResponse(out string) (summarizerResponse, error) {
+	var resp summarizerResponse
+	if err := json.Unmarshal([]byte(strings.TrimSpace(out)), &resp); err == nil {
+		return resp, nil
+	}
+	for _, line := range strings.Split(out, "\n") {
+		line = strings.TrimSpace(line)
+		if !strings.HasPrefix(line, "{") || !strings.HasSuffix(line, "}") {
+			continue
+		}
+		if err := json.Unmarshal([]byte(line), &resp); err == nil {
+			return resp, nil
+		}
+	}
+	return resp, fmt.Errorf("summary output was not JSON")
+}
+
+func summaryIdleState(s string) IdleState {
+	switch strings.ToUpper(strings.TrimSpace(s)) {
+	case "IDLE":
+		return StateIdle
+	case "PERMISSION":
+		return StatePermission
+	case "THINKING":
+		return StateThinking
+	case "WORKING":
+		return StateWorking
+	case "ERROR":
+		return StateError
+	default:
+		return StateUnknown
+	}
+}

internal/app/summarizer_test.go

@@ -0,0 +1,125 @@
+package app
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/hjbdev/patterm/internal/preset"
+)
+
+func TestParseSummarizerResponseAllowsWrappedJSON(t *testing.T) {
+	resp, err := parseSummarizerResponse("log\n{\"summary\":\"Waiting for tests\",\"state\":\"WORKING\"}\n")
+	if err != nil {
+		t.Fatalf("parseSummarizerResponse: %v", err)
+	}
+	if resp.Summary != "Waiting for tests" || summaryIdleState(resp.State) != StateWorking {
+		t.Fatalf("response = %+v", resp)
+	}
+}
+
+func TestCompactSummaryTextDropsControlAndRedundantWhitespace(t *testing.T) {
+	got := compactSummaryText("hello\x00 world  \n\n\n\x1b[31mred\x1b[0m\n")
+	if strings.ContainsRune(got, '\x00') {
+		t.Fatalf("control byte survived: %q", got)
+	}
+	if strings.Contains(got, "\n\n\n") {
+		t.Fatalf("redundant blanks survived: %q", got)
+	}
+	if strings.Contains(got, "\x1b") {
+		t.Fatalf("ansi survived: %q", got)
+	}
+}
+
+func TestWrapSidebarSummaryKeepsWordBoundaries(t *testing.T) {
+	got := wrapSidebarSummary("alpha beta gamma delta", 12)
+	want := []string{"alpha beta", "gamma delta"}
+	if len(got) != len(want) {
+		t.Fatalf("lines = %#v", got)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("line %d = %q want %q", i, got[i], want[i])
+		}
+	}
+	long := wrapSidebarSummary("supercalifragilistic short", 8)
+	if len(long) == 0 || strings.Contains(strings.Join(long, ""), "…") {
+		t.Fatalf("long word should wrap without ellipsis: %#v", long)
+	}
+	for _, line := range long {
+		if visibleLen(line) > 8 {
+			t.Fatalf("line %q exceeds width", line)
+		}
+	}
+}
+
+func TestSummaryTextForSelectsChildAndClips(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	cfg := defaultSettings()
+	st := &uiState{
+		sess:     sess,
+		settings: cfg,
+		summaries: newSummaryManager(sess, t.TempDir(), preset.Set{}, func() autoSummarySettings {
+			return cfg.AutoSummary.clone()
+		}, nil, nil),
+	}
+	st.summaries.mu.Lock()
+	st.summaries.entries["a1"] = &summaryEntry{state: summaryState{Text: " alpha summary "}}
+	st.summaries.entries["a2"] = &summaryEntry{state: summaryState{Text: "beta summary"}}
+	st.summaries.entries["empty"] = &summaryEntry{state: summaryState{Text: "   "}}
+	st.summaries.entries["long"] = &summaryEntry{state: summaryState{Text: "abcdefghijklmnopqrstuvwxyz"}}
+	st.summaries.mu.Unlock()
+
+	if got := st.summaryTextFor("a2", 20); got != "beta summary" {
+		t.Fatalf("summaryTextFor(a2) = %q, want beta summary", got)
+	}
+	if got := st.summaryTextFor("empty", 20); got != "" {
+		t.Fatalf("summaryTextFor(empty) = %q, want empty", got)
+	}
+	if got := st.summaryTextFor("long", 8); got != "abcdefg…" {
+		t.Fatalf("summaryTextFor(long) = %q, want abcdefg…", got)
+	}
+
+	st.settingsMu.Lock()
+	st.settings.AutoSummary.Enabled = false
+	st.settingsMu.Unlock()
+	if got := st.summaryTextFor("a1", 20); got != "" {
+		t.Fatalf("summaryTextFor disabled = %q, want empty", got)
+	}
+}
+
+func TestSummaryManagerArmsOnlyTrackedTopLevelAgents(t *testing.T) {
+	sess := NewSession(t.TempDir(), "test")
+	c := newChildEntry("a1", "agent", KindAgent, []string{"fake"}, nil, "", "", "")
+	running := StatusRunning
+	c.status.Store(&running)
+	sess.children[c.ID] = c
+	sess.order = append(sess.order, c.ID)
+	cfg := defaultSettings().AutoSummary
+	m := newSummaryManager(sess, t.TempDir(), preset.Set{}, func() autoSummarySettings {
+		return cfg.clone()
+	}, nil, nil)
+	m.ObserveHumanInput(c.ID, []byte("please summarize"))
+	if got := m.Summary(c.ID); got.Text != "" {
+		t.Fatalf("untracked agent should not update summary state: %+v", got)
+	}
+	m.RegisterChild(c)
+	m.ObserveHumanInput(c.ID, []byte("please summarize"))
+	m.ObserveOutput(c.ID)
+	m.mu.Lock()
+	e := m.entries[c.ID]
+	m.mu.Unlock()
+	if e == nil || !e.armed || !e.dirty {
+		t.Fatalf("tracked top-level agent not armed/dirty: %+v", e)
+	}
+
+	sub := newChildEntry("a2", "sub", KindAgent, []string{"fake"}, nil, c.ID, "", "")
+	sub.status.Store(&running)
+	m.RegisterChild(sub)
+	m.ObserveHumanInput(sub.ID, []byte("please summarize"))
+	m.mu.Lock()
+	_, ok := m.entries[sub.ID]
+	m.mu.Unlock()
+	if ok {
+		t.Fatal("sub-agent should not get a summary entry")
+	}
+}

internal/app/tabbar.go

@@ -4,12 +4,13 @@ import (
 	"fmt"
 	"os"
 	"strings"
+	"time"
 	"unicode/utf8"
 )
 
-// Two-row tab bar: labels row, underline row. The PTY viewport's top
+// Three-row tab bar: labels row, active-thread summary row, underline row. The PTY viewport's top
 // row is therefore mainTop == tabBarRows + 1.
-const tabBarRows = 2
+const tabBarRows = 3
 
 // drawTabBar renders the top tab strip across the full host width.
 // Tabs share the available width with a flex layout — each visible
@@ -17,9 +18,17 @@ const tabBarRows = 2
 // to the leftmost tabs so the strip fills the screen edge-to-edge.
 // A trailing "+ new" hint sits in the rightmost reserved slot.
 func (st *uiState) drawTabBar() {
+	var entry time.Time
+	if st.metrics != nil {
+		entry = time.Now()
+	}
 	st.mu.Lock()
 	palOpen := st.palette != nil
-	focus := st.focusedID
+	// Highlight the top-level agent tab even when focus has stepped
+	// into a sub-agent (or a Processes pane entry). activeAgentID walks
+	// the parent chain to the root, so the user always sees which tab
+	// their current thread belongs to.
+	focus := st.activeAgentID
 	st.mu.Unlock()
 	if palOpen {
 		return
@@ -50,12 +59,14 @@ func (st *uiState) drawTabBar() {
 	newHintW := utf8.RuneCountInString(newHint) + 2 // " + new " framing
 
 	type tabRect struct {
-		startCol int
-		width    int
-		label    string
-		active   bool
+		childID    string
+		startCol   int
+		width      int
+		label      string
+		glyph      string
+		glyphStyle string
+		active     bool
 	}
-
 	// Reserve space at the right edge for "+ new". If there are too
 	// many tabs to fit even at minTabWidth, drop tabs from the right
 	// until they do. The current focus stays visible.
@@ -105,9 +116,16 @@ func (st *uiState) drawTabBar() {
 			if i < extra {
 				w++
 			}
+			active := c.ID == focus
+			glyph, glyphStyle := tabIdleGlyph(c.IdleState(), active)
 			label := c.DisplayName()
 			labelW := utf8.RuneCountInString(label)
-			maxLabelW := w - 2 // one pad on each side
+			// Reserve room for the glyph + its trailing space when present
+			// (1 + 1 runes), on top of the one-cell pad on each side.
+			maxLabelW := w - 2
+			if glyph != "" {
+				maxLabelW -= 2
+			}
 			if maxLabelW < 1 {
 				maxLabelW = 1
 			}
@@ -120,17 +138,21 @@ func (st *uiState) drawTabBar() {
 				labelW = utf8.RuneCountInString(label)
 			}
 			tabs = append(tabs, tabRect{
-				startCol: col,
-				width:    w,
-				label:    label,
-				active:   c.ID == focus,
+				childID:    c.ID,
+				startCol:   col,
+				width:      w,
+				label:      label,
+				glyph:      glyph,
+				glyphStyle: glyphStyle,
+				active:     active,
 			})
 			col += w
 		}
 	}
 
 	var b strings.Builder
-	// Clear both rows so a stale label from the previous frame can't
+	// Clear all tab-bar rows so stale labels or summaries from the
+	// previous frame can't
 	// bleed through. Use ECH clamped to `width` (= childCols) instead of
 	// `\x1b[2K`: 2K wipes the entire line including the sidebar columns,
 	// and if drawSidebar's chrome cache is fresh it won't repaint to
@@ -138,32 +160,47 @@ func (st *uiState) drawTabBar() {
 	// and content should be.
 	fmt.Fprintf(&b, "\x1b[1;1H\x1b[%dX", width)
 	fmt.Fprintf(&b, "\x1b[2;1H\x1b[%dX", width)
+	fmt.Fprintf(&b, "\x1b[3;1H\x1b[%dX", width)
 
 	for _, t := range tabs {
-		// Row 1: centre-ish label inside the tab cell.
+		// Row 1: centre-ish glyph+label inside the tab cell.
 		labelW := utf8.RuneCountInString(t.label)
-		leftPad := (t.width - labelW) / 2
+		visibleW := labelW
+		if t.glyph != "" {
+			visibleW += 2 // glyph + separator space
+		}
+		leftPad := (t.width - visibleW) / 2
 		if leftPad < 1 {
 			leftPad = 1
 		}
-		rightPad := t.width - labelW - leftPad
+		rightPad := t.width - visibleW - leftPad
 		if rightPad < 0 {
 			rightPad = 0
 		}
-		fmt.Fprintf(&b, "\x1b[1;%dH", t.startCol)
+		cellStyle := styleHint
 		if t.active {
-			b.WriteString(styleActive)
-		} else {
-			b.WriteString(styleHint)
+			cellStyle = styleActive
 		}
+		fmt.Fprintf(&b, "\x1b[1;%dH", t.startCol)
+		b.WriteString(cellStyle)
 		b.WriteString(strings.Repeat(" ", leftPad))
+		if t.glyph != "" {
+			// Glyph uses its own colour so error/permission states pop
+			// regardless of tab focus, matching the sidebar's vocabulary.
+			b.WriteString(styleReset)
+			b.WriteString(t.glyphStyle)
+			b.WriteString(t.glyph)
+			b.WriteString(styleReset)
+			b.WriteString(cellStyle)
+			b.WriteString(" ")
+		}
 		b.WriteString(t.label)
 		b.WriteString(strings.Repeat(" ", rightPad))
 		b.WriteString(styleReset)
 
-		// Row 2: underline. Thick accent for the active tab, faint
+		// Row 3: underline. Thick accent for the active tab, faint
 		// border for the rest.
-		fmt.Fprintf(&b, "\x1b[2;%dH", t.startCol)
+		fmt.Fprintf(&b, "\x1b[3;%dH", t.startCol)
 		if t.active {
 			b.WriteString(styleAccent)
 			b.WriteString(strings.Repeat("━", t.width))
@@ -180,20 +217,59 @@ func (st *uiState) drawTabBar() {
 		fmt.Fprintf(&b, "\x1b[1;%dH %s%s%s ", hintCol, styleDim, newHint, styleReset)
 		// Underline continues faintly under the hint so the strip
 		// reads as one bar.
-		fmt.Fprintf(&b, "\x1b[2;%dH%s%s%s",
+		fmt.Fprintf(&b, "\x1b[3;%dH%s%s%s",
 			hintCol, styleBorder, strings.Repeat("─", newHintW), styleReset)
 	}
 
+	for _, tab := range tabs {
+		summaryWidth := tab.width - 2
+		if summary := st.summaryTextFor(tab.childID, summaryWidth); summary != "" {
+			fmt.Fprintf(&b, "\x1b[2;%dH %s%s%s", tab.startCol, styleDim, summary, styleReset)
+		}
+	}
+
 	frame := b.String()
 	st.chromeCacheMu.Lock()
 	if frame == st.tabBarCache {
 		st.chromeCacheMu.Unlock()
+		if st.metrics != nil {
+			st.metrics.recordTabbar(time.Since(entry), true)
+		}
 		return
 	}
 	st.tabBarCache = frame
 	st.chromeCacheMu.Unlock()
+	if st.metrics != nil {
+		defer func() { st.metrics.recordTabbar(time.Since(entry), false) }()
+	}
 
 	st.outMu.Lock()
 	defer st.outMu.Unlock()
 	fmt.Fprintf(os.Stdout, "\x1b7%s\x1b8", frame)
 }
+
+// tabIdleGlyph returns the one-rune state indicator (and its SGR style)
+// to render before a tab's label. Mirrors the sidebar's vocabulary so
+// users learn the symbols in one place: ✕ error, ? permission, ◐
+// thinking, ○ idle, ● working. Returns ("", "") for StateUnknown so the
+// first frame after spawn doesn't show a misleading badge.
+func tabIdleGlyph(state IdleState, active bool) (string, string) {
+	base := styleHint
+	if active {
+		base = styleAccent
+	}
+	switch state {
+	case StateError:
+		return "✕", styleError
+	case StatePermission:
+		return "?", styleAccent
+	case StateThinking:
+		return "◐", base
+	case StateIdle:
+		return "○", base
+	case StateWorking:
+		return "●", base
+	default:
+		return "", ""
+	}
+}

internal/app/timers.go

@@ -55,9 +55,10 @@ type pendingTimer struct {
 type timerManager struct {
 	sess *Session
 
-	mu     sync.Mutex
-	nextID int
-	timers map[string]*pendingTimer
+	mu      sync.Mutex
+	nextID  int
+	timers  map[string]*pendingTimer
+	changes chan struct{}
 
 	// fireFn is the callback used to deliver the body to the owning
 	// process. Decoupled so tests can substitute a recorder. Defaults
@@ -67,13 +68,25 @@ type timerManager struct {
 
 func newTimerManager(sess *Session) *timerManager {
 	m := &timerManager{
-		sess:   sess,
-		timers: make(map[string]*pendingTimer),
+		sess:    sess,
+		timers:  make(map[string]*pendingTimer),
+		changes: make(chan struct{}, 1),
 	}
 	m.fireFn = defaultFireFn
 	return m
 }
 
+func (m *timerManager) changeEvents() <-chan struct{} {
+	return m.changes
+}
+
+func (m *timerManager) notifyChanged() {
+	select {
+	case m.changes <- struct{}{}:
+	default:
+	}
+}
+
 func defaultFireFn(owner *Child, body, label string) {
 	if owner == nil || !owner.IsLive() {
 		return
@@ -121,6 +134,7 @@ func (m *timerManager) TimerSet(ownerID string, body, label string, seconds floa
 	m.timers[id] = t
 	m.mu.Unlock()
 	t.rt = time.AfterFunc(d, func() { m.fireDelay(id) })
+	m.notifyChanged()
 	return id, nil
 }
 
@@ -136,6 +150,7 @@ func (m *timerManager) fireDelay(id string) {
 	body, label := t.body, t.label
 	delete(m.timers, id)
 	m.mu.Unlock()
+	m.notifyChanged()
 	m.fireFn(owner, body, label)
 }
 
@@ -214,6 +229,7 @@ func (m *timerManager) registerIdleTimer(kind pendingTimerKind, ownerID, body, l
 	}
 	m.timers[id] = t
 	m.mu.Unlock()
+	m.notifyChanged()
 	resp.ID = id
 	resp.Status = "pending"
 	return resp, nil
@@ -231,6 +247,7 @@ func (m *timerManager) fireIdleMaxWait(id string) {
 	body, label := t.body, t.label
 	delete(m.timers, id)
 	m.mu.Unlock()
+	m.notifyChanged()
 	m.fireFn(owner, body, label)
 }
 
@@ -291,11 +308,79 @@ func (m *timerManager) onChildStateChanged(childID string, state IdleState) {
 		delete(m.timers, id)
 	}
 	m.mu.Unlock()
+	if len(firedIDs) > 0 {
+		m.notifyChanged()
+	}
 	for _, f := range fires {
 		m.fireFn(f.owner, f.body, f.label)
 	}
 }
 
+// onChildClosed drops pending timer references to childID. Called
+// from Session.Close (and the terminal-corpse cleanup in reapChild)
+// via the session listener bus — a deliberate signal from the host
+// that childID is gone and the parent is not waiting on it anymore.
+//
+// Semantics:
+//   - timers owned by childID are cancelled and deleted: their owner
+//     is gone, so even if defaultFireFn's IsLive guard would no-op
+//     the delivery, the entry has no business surviving a close.
+//   - timers watching childID have childID pruned from t.watched
+//     (and t.idleBaseline). If t.watched becomes empty the timer is
+//     cancelled and deleted; we deliberately do NOT synthesise a
+//     fire here. The parent already received any legitimate idle
+//     transition before close_process — see allWatchedIdleLocked's
+//     "treat as satisfied" comment, which only applies to a
+//     concurrent re-evaluation, not to this explicit-removal hook.
+//
+// The natural-exit path (reapChild → emitExit for agent/command
+// kinds) is NOT routed through here: the classifier emits a final
+// idle transition on exit, which fires and deletes any watching
+// timers exactly once. Cancelling on exit would swallow that
+// legitimate fire and leave the parent never notified.
+func (m *timerManager) onChildClosed(childID string) {
+	m.mu.Lock()
+	changed := false
+	for id, t := range m.timers {
+		if t.ownerID == childID {
+			if t.rt != nil {
+				t.rt.Stop()
+				t.rt = nil
+			}
+			t.status = timerStatusCanceled
+			delete(m.timers, id)
+			changed = true
+			continue
+		}
+		if !contains(t.watched, childID) {
+			continue
+		}
+		pruned := t.watched[:0]
+		for _, w := range t.watched {
+			if w != childID {
+				pruned = append(pruned, w)
+			}
+		}
+		t.watched = pruned
+		if t.idleBaseline != nil {
+			delete(t.idleBaseline, childID)
+		}
+		changed = true
+		if len(t.watched) == 0 {
+			if t.rt != nil {
+				t.rt.Stop()
+				t.rt = nil
+			}
+			t.status = timerStatusCanceled
+			delete(m.timers, id)
+		}
+	}
+	m.mu.Unlock()
+	if changed {
+		m.notifyChanged()
+	}
+}
+
 // allWatchedIdleLocked reports whether every watched child is now
 // idle. Called with m.mu held — uses live Child.IdleState() under the
 // child's own atomic, not under m.mu.
@@ -315,19 +400,21 @@ func (m *timerManager) allWatchedIdleLocked(t *pendingTimer) bool {
 // TimerCancel removes a pending or paused timer owned by ownerID.
 func (m *timerManager) TimerCancel(ownerID, id string) error {
 	m.mu.Lock()
-	defer m.mu.Unlock()
 	t, ok := m.timers[id]
 	if !ok {
+		m.mu.Unlock()
 		return mcp.Errorf(mcp.ErrorKindNotFound, "no such timer %q", id)
 	}
 	// Empty ownerID = top-level orchestrator caller (e.g. a non-agent
 	// MCP client); allow it to manage every timer in the session.
 	// Otherwise the caller's own id must match the timer's owner.
 	if ownerID != "" && t.ownerID != ownerID {
+		m.mu.Unlock()
 		return mcp.Errorf(mcp.ErrorKindRoleForbidden, "timer %q is not owned by caller", id)
 	}
 	if t.status == timerStatusFired || t.status == timerStatusCanceled {
 		// Cancelling a fired/cancelled timer is idempotent.
+		m.mu.Unlock()
 		return nil
 	}
 	if t.rt != nil {
@@ -336,6 +423,8 @@ func (m *timerManager) TimerCancel(ownerID, id string) error {
 	}
 	t.status = timerStatusCanceled
 	delete(m.timers, id)
+	m.mu.Unlock()
+	m.notifyChanged()
 	return nil
 }
 
@@ -343,18 +432,20 @@ func (m *timerManager) TimerCancel(ownerID, id string) error {
 // keeps the timer in the registry.
 func (m *timerManager) TimerPause(ownerID, id string) error {
 	m.mu.Lock()
-	defer m.mu.Unlock()
 	t, ok := m.timers[id]
 	if !ok {
+		m.mu.Unlock()
 		return mcp.Errorf(mcp.ErrorKindNotFound, "no such timer %q", id)
 	}
 	// Empty ownerID = top-level orchestrator caller (e.g. a non-agent
 	// MCP client); allow it to manage every timer in the session.
 	// Otherwise the caller's own id must match the timer's owner.
 	if ownerID != "" && t.ownerID != ownerID {
+		m.mu.Unlock()
 		return mcp.Errorf(mcp.ErrorKindRoleForbidden, "timer %q is not owned by caller", id)
 	}
 	if t.status != timerStatusPending {
+		m.mu.Unlock()
 		return mcp.Errorf(mcp.ErrorKindInvalidArgs, "timer %q is not pending", id)
 	}
 	if t.rt != nil {
@@ -370,6 +461,8 @@ func (m *timerManager) TimerPause(ownerID, id string) error {
 		t.pausedWasMaxWait = t.kind != timerKindDelay
 	}
 	t.status = timerStatusPaused
+	m.mu.Unlock()
+	m.notifyChanged()
 	return nil
 }
 
@@ -448,6 +541,7 @@ func (m *timerManager) TimerResume(ownerID, id string) error {
 		delete(m.timers, id)
 	}
 	m.mu.Unlock()
+	m.notifyChanged()
 	if fireNow {
 		m.fireFn(owner, body, label)
 	}
@@ -467,14 +561,16 @@ func (m *timerManager) TimerList(ownerID string) []mcp.TimerInfo {
 		if t.status != timerStatusPending && t.status != timerStatusPaused {
 			continue
 		}
+		body, bodyTruncated := timerBodyPreview(t.body)
 		info := mcp.TimerInfo{
-			ID:         t.id,
-			Label:      t.label,
-			Body:       t.body,
-			Kind:       string(t.kind),
-			Status:     t.status,
-			OwnerID:    t.ownerID,
-			WatchedIDs: append([]string(nil), t.watched...),
+			ID:            t.id,
+			Label:         t.label,
+			Body:          body,
+			BodyTruncated: bodyTruncated,
+			Kind:          string(t.kind),
+			Status:        t.status,
+			OwnerID:       t.ownerID,
+			WatchedIDs:    append([]string(nil), t.watched...),
 		}
 		if t.status == timerStatusPending && !t.firesAt.IsZero() {
 			info.FiresAtUnixMS = t.firesAt.UnixMilli()
@@ -487,6 +583,14 @@ func (m *timerManager) TimerList(ownerID string) []mcp.TimerInfo {
 	return out
 }
 
+func timerBodyPreview(body string) (string, bool) {
+	const max = 500
+	if len(body) <= max {
+		return body, false
+	}
+	return body[:max], true
+}
+
 // activeForChild returns the nearest pending or paused timer attached
 // to child id (either owned by it or watching it). Used by the sidebar
 // for the "⏱ 12s" indicator. nil when none.
@@ -528,6 +632,56 @@ func (m *timerManager) activeForChild(id string) *mcp.TimerInfo {
 	return &info
 }
 
+const (
+	timerSidebarMinRefresh       = 50 * time.Millisecond
+	timerSidebarSubsecondRefresh = 100 * time.Millisecond
+)
+
+func nextTimerSidebarLabelChange(d time.Duration) time.Duration {
+	if d <= 0 {
+		return 0
+	}
+	if d < time.Second {
+		if d < timerSidebarSubsecondRefresh {
+			return d
+		}
+		return timerSidebarSubsecondRefresh
+	}
+
+	step := time.Second
+	if d >= time.Hour {
+		step = time.Hour
+	} else if d >= time.Minute {
+		step = time.Minute
+	}
+	wait := d % step
+	if wait <= 0 || wait < timerSidebarMinRefresh {
+		return timerSidebarMinRefresh
+	}
+	return wait
+}
+
+func (m *timerManager) nextSidebarRefreshAfter(now time.Time) (time.Duration, bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	var best time.Duration
+	found := false
+	for _, t := range m.timers {
+		if t.status != timerStatusPending || t.firesAt.IsZero() {
+			continue
+		}
+		wait := nextTimerSidebarLabelChange(t.firesAt.Sub(now))
+		if wait <= 0 {
+			wait = timerSidebarMinRefresh
+		}
+		if !found || wait < best {
+			best = wait
+			found = true
+		}
+	}
+	return best, found
+}
+
 func isIdleState(s IdleState) bool {
 	return s == StateIdle
 }

internal/app/timers_test.go

@@ -65,6 +65,93 @@ func newTestManager(t *testing.T) (*Session, *timerManager, *recorderFire) {
 	return sess, mgr, rec
 }
 
+func waitTimerChange(t *testing.T, mgr *timerManager) {
+	t.Helper()
+	select {
+	case <-mgr.changeEvents():
+	case <-time.After(time.Second):
+		t.Fatal("timed out waiting for timer change signal")
+	}
+}
+
+func TestNextTimerSidebarLabelChange(t *testing.T) {
+	tests := []struct {
+		name string
+		d    time.Duration
+		want time.Duration
+	}{
+		{name: "minutes", d: 2*time.Minute + 10*time.Second, want: 10 * time.Second},
+		{name: "minute_to_seconds", d: time.Minute + 500*time.Millisecond, want: 500 * time.Millisecond},
+		{name: "seconds", d: 59*time.Second + 500*time.Millisecond, want: 500 * time.Millisecond},
+		{name: "subsecond", d: 500 * time.Millisecond, want: timerSidebarSubsecondRefresh},
+		{name: "nearly_done", d: 30 * time.Millisecond, want: 30 * time.Millisecond},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := nextTimerSidebarLabelChange(tt.d); got != tt.want {
+				t.Fatalf("nextTimerSidebarLabelChange(%s) = %s, want %s", tt.d, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestTimerSidebarRefreshAfterUsesSoonestActiveBoundary(t *testing.T) {
+	_, mgr, _ := newTestManager(t)
+	now := time.Unix(123, 0)
+	mgr.mu.Lock()
+	mgr.timers["slow"] = &pendingTimer{
+		id:      "slow",
+		status:  timerStatusPending,
+		firesAt: now.Add(2*time.Minute + 10*time.Second),
+	}
+	mgr.timers["fast"] = &pendingTimer{
+		id:      "fast",
+		status:  timerStatusPending,
+		firesAt: now.Add(59*time.Second + 500*time.Millisecond),
+	}
+	mgr.timers["paused"] = &pendingTimer{
+		id:      "paused",
+		status:  timerStatusPaused,
+		firesAt: now.Add(100 * time.Millisecond),
+	}
+	mgr.mu.Unlock()
+
+	got, ok := mgr.nextSidebarRefreshAfter(now)
+	if !ok {
+		t.Fatal("nextSidebarRefreshAfter did not find active timers")
+	}
+	if got != 500*time.Millisecond {
+		t.Fatalf("nextSidebarRefreshAfter = %s, want 500ms", got)
+	}
+}
+
+func TestTimerManagerSignalsChangesForSidebar(t *testing.T) {
+	sess, mgr, _ := newTestManager(t)
+	owner := fakeChild("p_owner")
+	addChild(sess, owner)
+
+	id, err := mgr.TimerSet("p_owner", "x", "", 60)
+	if err != nil {
+		t.Fatalf("TimerSet: %v", err)
+	}
+	waitTimerChange(t, mgr)
+
+	if err := mgr.TimerPause("p_owner", id); err != nil {
+		t.Fatalf("TimerPause: %v", err)
+	}
+	waitTimerChange(t, mgr)
+
+	if err := mgr.TimerResume("p_owner", id); err != nil {
+		t.Fatalf("TimerResume: %v", err)
+	}
+	waitTimerChange(t, mgr)
+
+	if err := mgr.TimerCancel("p_owner", id); err != nil {
+		t.Fatalf("TimerCancel: %v", err)
+	}
+	waitTimerChange(t, mgr)
+}
+
 func TestTimerSetDelivers(t *testing.T) {
 	sess, mgr, rec := newTestManager(t)
 	c := fakeChild("p_owner")
@@ -411,3 +498,178 @@ func TestTimerRecordsRemovedOnIdleFire(t *testing.T) {
 		t.Fatalf("fired idle timer %s was not removed from registry", resp.ID)
 	}
 }
+
+// TestTimerCloseChildPrunesWatched covers the happy partial-prune
+// case: an idle_any timer watches two children, one is closed, the
+// timer stays pending and the remaining child can still satisfy it.
+func TestTimerCloseChildPrunesWatched(t *testing.T) {
+	sess, mgr, rec := newTestManager(t)
+	owner := fakeChild("p_owner")
+	a := fakeChild("p_a")
+	b := fakeChild("p_b")
+	addChild(sess, owner)
+	addChild(sess, a)
+	addChild(sess, b)
+	working := StateWorking
+	a.idleState.Store(&working)
+	b.idleState.Store(&working)
+
+	resp, err := mgr.TimerFireWhenIdleAny("p_owner", "one done", "", []string{"p_a", "p_b"}, 0)
+	if err != nil {
+		t.Fatalf("TimerFireWhenIdleAny: %v", err)
+	}
+
+	mgr.onChildClosed("p_a")
+
+	mgr.mu.Lock()
+	t1, ok := mgr.timers[resp.ID]
+	if !ok {
+		mgr.mu.Unlock()
+		t.Fatalf("timer was removed but still has live watched")
+	}
+	watched := append([]string(nil), t1.watched...)
+	mgr.mu.Unlock()
+	if len(watched) != 1 || watched[0] != "p_b" {
+		t.Fatalf("watched after close: %v, want [p_b]", watched)
+	}
+	if got := rec.snapshot(); len(got) != 0 {
+		t.Fatalf("close synthesised a fire: %+v", got)
+	}
+
+	// p_b can still satisfy the timer.
+	idle := StateIdle
+	b.idleState.Store(&idle)
+	mgr.onChildStateChanged("p_b", StateIdle)
+	if got := rec.snapshot(); len(got) != 1 || got[0].Body != "one done" {
+		t.Fatalf("post-prune fire: %+v", got)
+	}
+}
+
+// TestTimerCloseLastWatchedCancels is the regression for the
+// reported stale-fire symptom: the only watched child is closed,
+// so the timer must be cancelled — no synthetic fire, and the
+// registry entry must be gone so a trailing classifier tick for the
+// removed child cannot re-deliver later.
+func TestTimerCloseLastWatchedCancels(t *testing.T) {
+	sess, mgr, rec := newTestManager(t)
+	owner := fakeChild("p_owner")
+	a := fakeChild("p_a")
+	addChild(sess, owner)
+	addChild(sess, a)
+	working := StateWorking
+	a.idleState.Store(&working)
+
+	resp, err := mgr.TimerFireWhenIdleAny("p_owner", "stale body", "", []string{"p_a"}, 0)
+	if err != nil {
+		t.Fatalf("TimerFireWhenIdleAny: %v", err)
+	}
+
+	mgr.onChildClosed("p_a")
+
+	mgr.mu.Lock()
+	_, stillThere := mgr.timers[resp.ID]
+	mgr.mu.Unlock()
+	if stillThere {
+		t.Fatalf("timer with no remaining watched should be removed")
+	}
+	if got := rec.snapshot(); len(got) != 0 {
+		t.Fatalf("close synthesised a fire: %+v", got)
+	}
+
+	// Simulate the trailing classifier tick for the now-closed child —
+	// must not fire.
+	mgr.onChildStateChanged("p_a", StateIdle)
+	if got := rec.snapshot(); len(got) != 0 {
+		t.Fatalf("trailing state change re-fired: %+v", got)
+	}
+}
+
+// TestTimerCloseChildIdleAllPartialPrune mirrors the idle_any
+// partial-prune for idle_all: pruning a watched child shrinks the
+// list; the remaining child going idle then satisfies the timer.
+func TestTimerCloseChildIdleAllPartialPrune(t *testing.T) {
+	sess, mgr, rec := newTestManager(t)
+	owner := fakeChild("p_owner")
+	a := fakeChild("p_a")
+	b := fakeChild("p_b")
+	addChild(sess, owner)
+	addChild(sess, a)
+	addChild(sess, b)
+	working := StateWorking
+	a.idleState.Store(&working)
+	b.idleState.Store(&working)
+
+	resp, err := mgr.TimerFireWhenIdleAll("p_owner", "all done", "", []string{"p_a", "p_b"}, 0)
+	if err != nil {
+		t.Fatalf("TimerFireWhenIdleAll: %v", err)
+	}
+	if resp.Status != "pending" {
+		t.Fatalf("status: got %q want pending", resp.Status)
+	}
+
+	mgr.onChildClosed("p_a")
+
+	idle := StateIdle
+	b.idleState.Store(&idle)
+	mgr.onChildStateChanged("p_b", StateIdle)
+	if got := rec.snapshot(); len(got) != 1 || got[0].Body != "all done" {
+		t.Fatalf("idle_all after partial prune: %+v", got)
+	}
+}
+
+// TestTimerCloseOwnerCancelsDelay ensures a delay timer is dropped
+// when its owner is closed: no delivery, registry empty, the
+// underlying time.Timer is stopped.
+func TestTimerCloseOwnerCancelsDelay(t *testing.T) {
+	sess, mgr, rec := newTestManager(t)
+	c := fakeChild("p_owner")
+	addChild(sess, c)
+	id, err := mgr.TimerSet("p_owner", "x", "", 0.1)
+	if err != nil {
+		t.Fatalf("TimerSet: %v", err)
+	}
+
+	mgr.onChildClosed("p_owner")
+
+	mgr.mu.Lock()
+	_, stillThere := mgr.timers[id]
+	mgr.mu.Unlock()
+	if stillThere {
+		t.Fatalf("delay timer was not removed when owner closed")
+	}
+	time.Sleep(200 * time.Millisecond) // past the original firesAt
+	if got := rec.snapshot(); len(got) != 0 {
+		t.Fatalf("delay timer fired after owner close: %+v", got)
+	}
+}
+
+// TestTimerCloseWatchedSubAgent is the exact shape of the reported
+// stale-fire bug: orchestrator registers a watcher on a sub-agent,
+// the sub-agent is closed, and the orchestrator must receive
+// nothing (no stale body delivered after close_process).
+func TestTimerCloseWatchedSubAgent(t *testing.T) {
+	sess, mgr, rec := newTestManager(t)
+	parent := fakeChild("p_owner")
+	sub := fakeChild("p_sub")
+	addChild(sess, parent)
+	addChild(sess, sub)
+	working := StateWorking
+	sub.idleState.Store(&working)
+
+	if _, err := mgr.TimerFireWhenIdleAny(
+		"p_owner",
+		"codex-review-591 finished. Read your own pane …",
+		"", []string{"p_sub"}, 0,
+	); err != nil {
+		t.Fatalf("TimerFireWhenIdleAny: %v", err)
+	}
+
+	mgr.onChildClosed("p_sub")
+
+	// Trailing classifier emission for the closed sub-agent must
+	// not deliver anything to the parent.
+	mgr.onChildStateChanged("p_sub", StateIdle)
+	if got := rec.snapshot(); len(got) != 0 {
+		t.Fatalf("stale fire delivered to parent after sub-agent close: %+v", got)
+	}
+}

internal/app/toast.go

@@ -0,0 +1,361 @@
+package app
+
+import (
+	"os"
+	"strings"
+	"sync"
+)
+
+// toastKind classifies a toast for styling and for migrating the
+// pre-existing flashError / flashTransient / notifyAttention call
+// sites onto the new stack.
+type toastKind int
+
+const (
+	toastInfo toastKind = iota
+	toastError
+	toastAttention
+)
+
+// toast is one entry in the host-level notification stack. Toasts
+// persist until the user dismisses them with Ctrl-N or the
+// "Clear notifications" palette command — there's no auto-expiry.
+type toast struct {
+	id   uint64
+	kind toastKind
+	text string
+}
+
+// toastStackCap caps how many toasts can be visible at once.
+// Older entries drop off the bottom when a new push would exceed it.
+const toastStackCap = 5
+
+// toastBoxMaxWidth bounds the rendered box width so a wide pane
+// doesn't produce huge toasts. Boxes shrink below this when the pane
+// is narrow.
+const toastBoxMaxWidth = 50
+
+// toastBoxMinWidth is the floor below which we refuse to render —
+// any narrower and there's not enough room for borders + content.
+const toastBoxMinWidth = 20
+
+// toastContentRows is how many lines of message body each toast box
+// reserves. The dismiss hint lives on the host status strip, so the
+// box itself is purely the message.
+const toastContentRows = 3
+
+// toastStack owns the ordered list of live toasts. Oldest at
+// index 0, newest (visually topmost) at the end. The stack's own
+// mutex is intentionally separate from uiState.mu so push / dismiss
+// can be called from any goroutine without participating in the
+// host's bigger lock-ordering rules.
+type toastStack struct {
+	mu    sync.Mutex
+	items []toast
+	next  uint64
+}
+
+func (s *toastStack) push(kind toastKind, text string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.next++
+	s.items = append(s.items, toast{id: s.next, kind: kind, text: text})
+	if len(s.items) > toastStackCap {
+		s.items = s.items[len(s.items)-toastStackCap:]
+	}
+}
+
+// dismissTop pops the most recent toast (the one rendered at the
+// top of the stack). Returns true if something was removed so
+// callers can decide whether to repaint.
+func (s *toastStack) dismissTop() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if len(s.items) == 0 {
+		return false
+	}
+	s.items = s.items[:len(s.items)-1]
+	return true
+}
+
+func (s *toastStack) clear() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if len(s.items) == 0 {
+		return false
+	}
+	s.items = s.items[:0]
+	return true
+}
+
+func (s *toastStack) snapshot() []toast {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if len(s.items) == 0 {
+		return nil
+	}
+	out := make([]toast, len(s.items))
+	copy(out, s.items)
+	return out
+}
+
+func (s *toastStack) length() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return len(s.items)
+}
+
+// notifyToast is the single entry point that the former flash
+// helpers now delegate to. It pushes onto the stack and triggers a
+// repaint of the focused surface so the new toast appears
+// immediately; the repaint path also re-renders the stack on top.
+func (st *uiState) notifyToast(kind toastKind, text string) {
+	st.toasts.push(kind, text)
+	st.refreshToastSurface()
+}
+
+// refreshToastSurface re-renders whatever surface the toasts are
+// drawn over (focused child, focused pad, or the empty-state
+// canvas). Each of those paths calls renderToasts at the end, so
+// the toast layer is always reapplied on top of a freshly-drawn
+// pane. Centralised so push / dismiss / clear share one code path.
+//
+// The status strip also gains/loses the "Ctrl-N · dismiss" hint as
+// the stack toggles between empty and non-empty, so we redraw it
+// here too rather than waiting for the chrome ticker.
+func (st *uiState) refreshToastSurface() {
+	st.mu.Lock()
+	focusedPad := st.focusedPad
+	focusedID := st.focusedID
+	palOpen := st.palette != nil
+	st.mu.Unlock()
+	if palOpen {
+		// Palette owns the whole screen while it's open; toasts will
+		// repaint via closePalette's restore path.
+		return
+	}
+	switch {
+	case focusedPad != "":
+		st.repaintFocusedPad()
+	case focusedID != "":
+		st.repaintFocused()
+	default:
+		st.renderEmptyState()
+	}
+	st.drawStatusLine()
+}
+
+// renderToasts draws the toast stack over the top-right of the
+// focused pane. Called from repaintFocused / repaintFocusedPad /
+// renderEmptyState after they finish so toasts always sit on top of
+// freshly-redrawn pane content. Safe to call when the stack is
+// empty (no-op).
+func (st *uiState) renderToasts() {
+	bytes := st.toastOverlayBytes()
+	if len(bytes) == 0 {
+		return
+	}
+	st.outMu.Lock()
+	defer st.outMu.Unlock()
+	_, _ = os.Stdout.Write(bytes)
+}
+
+// toastOverlayBytes builds the toast layer as a single byte buffer
+// without writing to stdout. Returns nil when the stack is empty or
+// the layout can't accommodate a box. Callers either write it
+// directly (renderToasts) or stitch it onto the end of another
+// stdout write so claude/codex/opencode redraws that paint over the
+// top-right region can't leave the toast half-erased.
+func (st *uiState) toastOverlayBytes() []byte {
+	items := st.toasts.snapshot()
+	if len(items) == 0 {
+		return nil
+	}
+	st.mu.Lock()
+	palOpen := st.palette != nil
+	st.mu.Unlock()
+	if palOpen {
+		return nil
+	}
+	layout := st.layoutSnapshot()
+	paneCols := int(layout.childCols())
+	paneRows := int(layout.childRows())
+	if paneCols < toastBoxMinWidth+2 || paneRows < toastContentRows+2 {
+		return nil
+	}
+	boxWidth := toastBoxMaxWidth
+	if max := paneCols - 4; max < boxWidth {
+		boxWidth = max
+	}
+	if boxWidth < toastBoxMinWidth {
+		return nil
+	}
+	contentWidth := boxWidth - 4 // 2 border cells + 2 inner padding
+	// Reserve two columns for the icon prefix on row 1 so wrapped rows
+	// indent under the body text rather than under the glyph.
+	const iconCols = 2
+	bodyRoom := contentWidth - iconCols
+	if bodyRoom < 1 {
+		return nil
+	}
+
+	var b strings.Builder
+	// Wrap the whole overlay in DECSET 2026 (synchronized output)
+	// brackets so terminals that support BSU/ESU buffer the box paint
+	// into a single frame — without this, claude's continuous redraws
+	// and our overlay race on each cell, producing visible flicker.
+	// Terminals that don't recognise 2026 ignore the brackets, so the
+	// fallback behaviour is the same as before.
+	b.WriteString("\x1b[?2026h\x1b7\x1b[?25l")
+
+	row := int(layout.mainTop) + 1
+	col := int(layout.mainLeft) + paneCols - boxWidth - 1
+	if col < int(layout.mainLeft) {
+		col = int(layout.mainLeft)
+	}
+
+	// Render newest first (visually on top), iterating items in
+	// reverse so the most recent push lands at the smallest row.
+	for idx := len(items) - 1; idx >= 0; idx-- {
+		t := items[idx]
+		height := toastContentRows + 2
+		// Stop if we'd run off the bottom of the pane.
+		if row+height > int(layout.mainTop)+paneRows {
+			break
+		}
+		border := toastBorderStyle(t.kind)
+		wrapped := wrapToastBody(t.text, bodyRoom)
+
+		// Top border.
+		moveTo(&b, row, col)
+		b.WriteString(border)
+		b.WriteString("╭")
+		b.WriteString(strings.Repeat("─", boxWidth-2))
+		b.WriteString("╮")
+		b.WriteString(styleReset)
+		row++
+
+		// Content rows. Row 0 carries the kind glyph; rows 1..N indent
+		// by iconCols spaces so wrapped text lines up under the body.
+		for i := 0; i < toastContentRows; i++ {
+			moveTo(&b, row, col)
+			b.WriteString(border)
+			b.WriteString("│")
+			b.WriteString(styleReset)
+			b.WriteString(" ")
+			if i == 0 {
+				b.WriteString(toastIcon(t.kind))
+			} else {
+				b.WriteString(strings.Repeat(" ", iconCols))
+			}
+			line := wrapped[i]
+			b.WriteString(line)
+			b.WriteString(strings.Repeat(" ", max(0, bodyRoom-visibleLen(line))))
+			b.WriteString(" ")
+			b.WriteString(border)
+			b.WriteString("│")
+			b.WriteString(styleReset)
+			row++
+		}
+
+		// Bottom border.
+		moveTo(&b, row, col)
+		b.WriteString(border)
+		b.WriteString("╰")
+		b.WriteString(strings.Repeat("─", boxWidth-2))
+		b.WriteString("╯")
+		b.WriteString(styleReset)
+		row++
+
+		// 1-row gap between stacked toasts.
+		row++
+	}
+
+	b.WriteString("\x1b[?25h\x1b8\x1b[?2026l")
+	return []byte(b.String())
+}
+
+func toastBorderStyle(kind toastKind) string {
+	switch kind {
+	case toastError:
+		return styleError
+	case toastAttention:
+		return styleAccent
+	default:
+		return styleBorder
+	}
+}
+
+// wrapToastBody word-wraps text into exactly toastContentRows lines,
+// each at most width visible runes wide. Short messages are padded
+// with empty trailing lines so callers can iterate a fixed-size
+// slice; messages that don't fit get ellipsized on the last line.
+func wrapToastBody(text string, width int) []string {
+	out := make([]string, toastContentRows)
+	if width < 1 {
+		return out
+	}
+	all := wrapToastWords(text, width)
+	if len(all) > toastContentRows {
+		all = all[:toastContentRows]
+		last := all[len(all)-1]
+		if visibleLen(last) >= width {
+			last = clipRunes(last, width-1) + "…"
+		} else {
+			last = last + "…"
+		}
+		all[len(all)-1] = last
+	}
+	for i, l := range all {
+		out[i] = l
+	}
+	return out
+}
+
+// wrapToastWords is a small word-wrapper sized for toast bodies:
+// greedy, breaks overlong words on rune boundaries, drops collapsing
+// whitespace via strings.Fields.
+func wrapToastWords(text string, width int) []string {
+	var lines []string
+	var cur string
+	flush := func() {
+		if cur != "" {
+			lines = append(lines, cur)
+			cur = ""
+		}
+	}
+	for _, word := range strings.Fields(text) {
+		for visibleLen(word) > width {
+			flush()
+			head := clipRunes(word, width)
+			lines = append(lines, head)
+			word = word[len(head):]
+		}
+		if word == "" {
+			continue
+		}
+		if cur == "" {
+			cur = word
+			continue
+		}
+		if visibleLen(cur)+1+visibleLen(word) <= width {
+			cur += " " + word
+			continue
+		}
+		flush()
+		cur = word
+	}
+	flush()
+	return lines
+}
+
+func toastIcon(kind toastKind) string {
+	switch kind {
+	case toastError:
+		return styleError + "✗ " + styleReset
+	case toastAttention:
+		return styleAccent + "! " + styleReset
+	default:
+		return styleHint + "• " + styleReset
+	}
+}

internal/app/toast_test.go

@@ -0,0 +1,164 @@
+package app
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestToastStackPushAndOrder(t *testing.T) {
+	var s toastStack
+	s.push(toastInfo, "one")
+	s.push(toastError, "two")
+	s.push(toastAttention, "three")
+
+	snap := s.snapshot()
+	if len(snap) != 3 {
+		t.Fatalf("snapshot len = %d, want 3", len(snap))
+	}
+	if snap[0].text != "one" || snap[1].text != "two" || snap[2].text != "three" {
+		t.Fatalf("snapshot order wrong: %#v", snap)
+	}
+	if snap[0].kind != toastInfo || snap[1].kind != toastError || snap[2].kind != toastAttention {
+		t.Fatalf("snapshot kinds wrong: %#v", snap)
+	}
+	// IDs strictly increase.
+	if !(snap[0].id < snap[1].id && snap[1].id < snap[2].id) {
+		t.Fatalf("ids not increasing: %#v", snap)
+	}
+}
+
+func TestToastStackCapDropsOldest(t *testing.T) {
+	var s toastStack
+	for i := 0; i < toastStackCap+3; i++ {
+		s.push(toastInfo, "msg")
+	}
+	snap := s.snapshot()
+	if len(snap) != toastStackCap {
+		t.Fatalf("len = %d, want %d", len(snap), toastStackCap)
+	}
+	// The earliest IDs should have been dropped, leaving the highest
+	// toastStackCap IDs.
+	for i := 1; i < len(snap); i++ {
+		if snap[i].id <= snap[i-1].id {
+			t.Fatalf("ordering broken after cap: %#v", snap)
+		}
+	}
+	// First retained id should be 4 (1,2,3 dropped; cap=5 leaves 4..8).
+	want := uint64(toastStackCap + 3 - toastStackCap + 1)
+	if snap[0].id != want {
+		t.Fatalf("first retained id = %d, want %d", snap[0].id, want)
+	}
+}
+
+func TestToastStackDismissTop(t *testing.T) {
+	var s toastStack
+	if s.dismissTop() {
+		t.Fatalf("dismissTop on empty stack returned true")
+	}
+	s.push(toastInfo, "a")
+	s.push(toastError, "b")
+	if !s.dismissTop() {
+		t.Fatalf("dismissTop returned false with items present")
+	}
+	snap := s.snapshot()
+	if len(snap) != 1 || snap[0].text != "a" {
+		t.Fatalf("after dismissTop: %#v", snap)
+	}
+	if !s.dismissTop() {
+		t.Fatalf("dismissTop on last item returned false")
+	}
+	if s.length() != 0 {
+		t.Fatalf("length after final dismiss = %d, want 0", s.length())
+	}
+}
+
+func TestToastStackClear(t *testing.T) {
+	var s toastStack
+	if s.clear() {
+		t.Fatalf("clear on empty returned true")
+	}
+	s.push(toastInfo, "a")
+	s.push(toastError, "b")
+	s.push(toastAttention, "c")
+	if !s.clear() {
+		t.Fatalf("clear returned false with items present")
+	}
+	if s.length() != 0 {
+		t.Fatalf("length after clear = %d, want 0", s.length())
+	}
+	if snap := s.snapshot(); snap != nil {
+		t.Fatalf("snapshot after clear = %#v, want nil", snap)
+	}
+}
+
+func TestToastStackSnapshotIsCopy(t *testing.T) {
+	var s toastStack
+	s.push(toastInfo, "a")
+	snap := s.snapshot()
+	snap[0].text = "mutated"
+	again := s.snapshot()
+	if again[0].text != "a" {
+		t.Fatalf("snapshot is not an independent copy: %#v", again)
+	}
+}
+
+func TestWrapToastBodyFixedHeight(t *testing.T) {
+	got := wrapToastBody("short", 20)
+	if len(got) != toastContentRows {
+		t.Fatalf("len = %d, want %d", len(got), toastContentRows)
+	}
+	if got[0] != "short" {
+		t.Fatalf("line 0 = %q, want \"short\"", got[0])
+	}
+	if got[1] != "" || got[2] != "" {
+		t.Fatalf("trailing pads not empty: %#v", got)
+	}
+}
+
+func TestWrapToastBodyWrapsOnWordBoundary(t *testing.T) {
+	got := wrapToastBody("the quick brown fox jumps over", 10)
+	// Expect greedy fill: "the quick" (9), "brown fox" (9), "jumps over" (10).
+	want := []string{"the quick", "brown fox", "jumps over"}
+	for i, w := range want {
+		if got[i] != w {
+			t.Fatalf("line %d = %q, want %q (full=%#v)", i, got[i], w, got)
+		}
+	}
+}
+
+func TestWrapToastBodyEllipsizesOverflow(t *testing.T) {
+	got := wrapToastBody("alpha beta gamma delta epsilon zeta eta theta", 6)
+	if len(got) != toastContentRows {
+		t.Fatalf("len = %d, want %d", len(got), toastContentRows)
+	}
+	last := got[toastContentRows-1]
+	if !strings.HasSuffix(last, "…") {
+		t.Fatalf("overflow should ellipsize last line, got %q (full=%#v)", last, got)
+	}
+	if visibleLen(last) > 6 {
+		t.Fatalf("last line %q exceeds width 6", last)
+	}
+}
+
+func TestWrapToastBodyBreaksOverlongWord(t *testing.T) {
+	got := wrapToastBody("supercalifragilistic", 6)
+	if got[0] != "superc" {
+		t.Fatalf("line 0 = %q, want \"superc\"", got[0])
+	}
+	if got[1] != "alifra" {
+		t.Fatalf("line 1 = %q, want \"alifra\"", got[1])
+	}
+	// Third line should hold the rest (possibly ellipsized).
+	if got[2] == "" {
+		t.Fatalf("line 2 unexpectedly empty: %#v", got)
+	}
+}
+
+func TestWrapToastBodyEmptyInput(t *testing.T) {
+	got := wrapToastBody("", 20)
+	for i, l := range got {
+		if l != "" {
+			t.Fatalf("line %d = %q, want \"\"", i, l)
+		}
+	}
+}

internal/app/viewport_renderer.go

@@ -33,6 +33,14 @@ type viewportRenderer struct {
 	// cache so the next drawSidebar repaints over the clobber.
 	scrolled bool
 
+	// childOnAlt tracks whether the focused child has entered its
+	// alternate screen (via ?47 / ?1047 / ?1049). Used to gate mouse-
+	// tracking-mode forwarding to the host: filter on primary so
+	// patterm's wheel-scrollback stays armed, forward on alt so codex
+	// (which disables mouse) lets the user select text and vim (which
+	// enables it) still gets mouse events.
+	childOnAlt bool
+
 	// skipUTF8 is set when the current multi-byte UTF-8 character started
 	// past the viewport's right edge. The starter byte was dropped, so
 	// the remaining continuation bytes must be dropped too instead of
@@ -65,6 +73,16 @@ func newViewportRenderer(l terminalLayout) *viewportRenderer {
 	return vr
 }
 
+// SetChildOnAlt seeds the renderer's view of the focused child's screen
+// side. Used when a new renderer is constructed for an already-running
+// child whose alt-screen transition we missed, so subsequent mouse-mode
+// toggles are filtered/forwarded according to the right side.
+func (vr *viewportRenderer) SetChildOnAlt(onAlt bool) {
+	vr.mu.Lock()
+	defer vr.mu.Unlock()
+	vr.childOnAlt = onAlt
+}
+
 func (vr *viewportRenderer) SetLayout(l terminalLayout) {
 	vr.mu.Lock()
 	defer vr.mu.Unlock()
@@ -236,15 +254,36 @@ func (vr *viewportRenderer) emitCSI() {
 			return
 		}
 		if isAltScreenMode(params) {
+			// Track the child's screen side so we know whether to filter
+			// or forward subsequent mouse-mode toggles. Entering alt
+			// disables host mouse reporting by default so codex (and
+			// any other alt-screen TUI that doesn't request mouse)
+			// allows the user to click-drag to select text. Alt-screen
+			// TUIs that want mouse (vim, less with -X) re-enable it
+			// via ?1000h after switching to alt — the forwarder below
+			// passes that through. Leaving alt re-arms host mouse for
+			// primary-screen wheel-scrollback.
+			wasAlt := vr.childOnAlt
+			vr.childOnAlt = final == 'h'
+			if !wasAlt && vr.childOnAlt {
+				vr.pending.WriteString("\x1b[?1000l\x1b[?1006l")
+			}
+			if wasAlt && !vr.childOnAlt {
+				vr.pending.WriteString("\x1b[?1000h\x1b[?1006h")
+			}
 			return
 		}
 		if isMouseTrackingMode(params) {
-			// Patterm owns mouse reporting on the host so wheel events keep
-			// flowing for scroll-viewport. The child's own emulator still
-			// observes the mode set/reset (it processes the same bytes we
-			// hand to ghostty_terminal_vt_write), so we know whether the
-			// child wants mouse input — we just don't let it disarm our
-			// host listener.
+			// On the child's primary screen patterm owns mouse reporting so
+			// wheel events keep flowing for in-pane scrollback — drop the
+			// child's toggle. On the alt screen the child should be free
+			// to enable mouse (vim, less) or disable it (codex); we forward
+			// the toggle to the host so click-and-drag selection works for
+			// alt-screen TUIs that don't want mouse, and mouse-aware ones
+			// still see the events they need.
+			if vr.childOnAlt {
+				vr.pending.Write(vr.buf)
+			}
 			return
 		}
 	}

internal/app/viewport_renderer_test.go

@@ -16,7 +16,7 @@ func bytesRepeat(b byte, n int) []byte {
 func TestViewportRendererShiftsCursor(t *testing.T) {
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
 	got := string(vr.Render([]byte("\x1b[H")))
-	if got != "\x1b[3;1H" {
+	if got != "\x1b[4;1H" {
 		t.Fatalf("CUP home: got %q", got)
 	}
 }
@@ -24,8 +24,36 @@ func TestViewportRendererShiftsCursor(t *testing.T) {
 func TestViewportRendererSwallowsAltScreenToggles(t *testing.T) {
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
 	got := string(vr.Render([]byte("a\x1b[?1049hb\x1b[?1049lc")))
+	// The ?1049h/l toggles themselves must not reach the host (patterm
+	// owns its own alt screen). On the transition we re-sync host mouse
+	// reporting so codex (which doesn't request mouse) lets the user
+	// drag-select; leaving alt re-arms it for primary-screen wheel
+	// scrollback.
+	want := "a\x1b[?1000l\x1b[?1006lb\x1b[?1000h\x1b[?1006hc"
+	if got != want {
+		t.Fatalf("alt-screen toggles: got %q want %q", got, want)
+	}
+}
+
+func TestViewportRendererMouseTrackingFilteredOnPrimary(t *testing.T) {
+	vr := newViewportRenderer(newTerminalLayout(120, 40))
+	got := string(vr.Render([]byte("a\x1b[?1000lb\x1b[?1000hc")))
 	if got != "abc" {
-		t.Fatalf("alt-screen toggles: got %q", got)
+		t.Fatalf("mouse mode on primary should be filtered: got %q", got)
+	}
+}
+
+func TestViewportRendererMouseTrackingForwardedOnAlt(t *testing.T) {
+	vr := newViewportRenderer(newTerminalLayout(120, 40))
+	// Enter alt; subsequent mouse-mode toggles should reach the host so
+	// alt-screen TUIs (vim, less) can run with mouse on, and selection-
+	// using ones (codex) stay with mouse off.
+	got := string(vr.Render([]byte("\x1b[?1049h\x1b[?1000lx\x1b[?1000hy")))
+	if !strings.Contains(got, "\x1b[?1000l") {
+		t.Fatalf("alt-screen mouse disable should reach host: %q", got)
+	}
+	if !strings.Contains(got, "\x1b[?1000h") {
+		t.Fatalf("alt-screen mouse enable should reach host: %q", got)
 	}
 }
 
@@ -38,7 +66,7 @@ func TestViewportRendererSwallowsOriginModeToggles(t *testing.T) {
 	if !strings.Contains(got, "a") || !strings.Contains(got, "b") || !strings.Contains(got, "c") {
 		t.Fatalf("origin-mode toggles should not drop surrounding text: got %q", got)
 	}
-	if strings.Count(got, "\x1b[3;1H") != 2 {
+	if strings.Count(got, "\x1b[4;1H") != 2 {
 		t.Fatalf("origin-mode set/reset should home inside the viewport twice: got %q", got)
 	}
 }
@@ -60,23 +88,23 @@ func TestViewportRendererOriginModeCUPUsesScrollTop(t *testing.T) {
 	if strings.Contains(got, "\x1b[?6h") {
 		t.Fatalf("origin-mode set leaked to host: %q", got)
 	}
-	if !strings.Contains(got, "\x1b[7;1H") {
-		t.Fatalf("CUP row 1 in origin mode should land at scrollTop row 5 shifted to host row 7: got %q", got)
+	if !strings.Contains(got, "\x1b[8;1H") {
+		t.Fatalf("CUP row 1 in origin mode should land at scrollTop row 5 shifted to host row 8: got %q", got)
 	}
 }
 
 func TestViewportRendererClearScreenIsViewportOnly(t *testing.T) {
-	// hostRows=7 leaves four viewport rows after the 2-row tab bar and
+	// hostRows=7 leaves three viewport rows after the 3-row tab bar and
 	// 1-row status reservation.
 	vr := newViewportRenderer(newTerminalLayout(20, 7))
 	got := string(vr.Render([]byte("\x1b[2J")))
 	if strings.Contains(got, "\x1b[2J") {
 		t.Fatalf("host clear-screen leaked through: %q", got)
 	}
-	if strings.Count(got, "\x1b[20X") != 4 {
+	if strings.Count(got, "\x1b[20X") != 3 {
 		t.Fatalf("clear rows: got %q", got)
 	}
-	if !strings.Contains(got, "\x1b[3;1H") || !strings.Contains(got, "\x1b[6;1H") {
+	if !strings.Contains(got, "\x1b[4;1H") || !strings.Contains(got, "\x1b[6;1H") {
 		t.Fatalf("clear did not target viewport rows: %q", got)
 	}
 }
@@ -112,13 +140,12 @@ func TestViewportRendererClearToEndIsViewportOnly(t *testing.T) {
 		t.Fatalf("host clear-to-end leaked through: %q", got)
 	}
 	// childCols == 19 (40 cols - 28 sidebar - 1 gap - 0-index fudge).
-	// Each of the 4 viewport rows should get a 19-cell erase.
 	// childCols == 11 with hostCols=40 (28 sidebar + 1 gap reserved).
-	// 4 viewport rows, but the cursor row uses ECH at cursor (col 1),
-	// so we expect 4 erases of 11 cells each.
+	// 3 viewport rows, but the cursor row uses ECH at cursor (col 1),
+	// so we expect 3 erases of 11 cells each.
 	count := strings.Count(got, "\x1b[11X")
-	if count != 4 {
-		t.Fatalf("expected 4 ECH-11 sequences, got %d in %q", count, got)
+	if count != 3 {
+		t.Fatalf("expected 3 ECH-11 sequences, got %d in %q", count, got)
 	}
 }
 
@@ -154,7 +181,7 @@ func TestViewportRendererClampsCUPColumn(t *testing.T) {
 	// column so the host cursor never lands in the sidebar.
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
 	got := string(vr.Render([]byte("\x1b[5;95H")))
-	if !strings.Contains(got, "\x1b[7;91H") {
+	if !strings.Contains(got, "\x1b[8;91H") {
 		t.Fatalf("CUP col 95 should clamp to 91 (childCols): got %q", got)
 	}
 }
@@ -249,7 +276,7 @@ func TestViewportRendererFlagsScrollVerbs(t *testing.T) {
 
 func TestViewportRendererFlagsLineFeedAtViewportBottomAsScrolling(t *testing.T) {
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
-	_ = vr.Render([]byte("\x1b[37;1H\n"))
+	_ = vr.Render([]byte("\x1b[36;1H\n"))
 	if !vr.TookScrollAction() {
 		t.Fatalf("LF at viewport bottom should flag scroll")
 	}
@@ -257,7 +284,7 @@ func TestViewportRendererFlagsLineFeedAtViewportBottomAsScrolling(t *testing.T)
 
 func TestViewportRendererDoesNotFlagLineFeedBeforeViewportBottom(t *testing.T) {
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
-	_ = vr.Render([]byte("\x1b[36;1H\n"))
+	_ = vr.Render([]byte("\x1b[35;1H\n"))
 	if vr.TookScrollAction() {
 		t.Fatalf("LF before viewport bottom should not flag scroll")
 	}
@@ -284,7 +311,7 @@ func TestViewportRendererClampsCUUAtViewportTop(t *testing.T) {
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
 	// CUP to viewport row 1 then CUU by 50.
 	got := string(vr.Render([]byte("\x1b[1;1H\x1b[50ACLOBBER")))
-	if !strings.Contains(got, "\x1b[3;1H") {
+	if !strings.Contains(got, "\x1b[4;1H") {
 		t.Fatalf("expected CUP shifted to mainTop: got %q", got)
 	}
 	// The CUU should have been swallowed (n clamped to 0 from row 1).
@@ -311,10 +338,10 @@ func TestViewportRendererClampsCUUPartial(t *testing.T) {
 }
 
 func TestViewportRendererClampsCUDAtViewportBottom(t *testing.T) {
-	// childRows=37 for layout(120, 40). Park cursor at row 37, ask for
+	// childRows=36 for layout(120, 40). Park cursor at row 36, ask for
 	// 10 down → safe step is 0.
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
-	got := string(vr.Render([]byte("\x1b[37;1H\x1b[10B")))
+	got := string(vr.Render([]byte("\x1b[36;1H\x1b[10B")))
 	if strings.Contains(got, "\x1b[10B") {
 		t.Fatalf("CUD past viewport bottom should be dropped: got %q", got)
 	}
@@ -335,10 +362,10 @@ func TestViewportRendererClampsCPLAndHomesColumn(t *testing.T) {
 
 func TestViewportRendererClampsCNL(t *testing.T) {
 	vr := newViewportRenderer(newTerminalLayout(120, 40))
-	// CUP to row 35 then CNL by 50 → safe step is 2 (childRows-35).
-	got := string(vr.Render([]byte("\x1b[35;10H\x1b[50E")))
+	// CUP to row 34 then CNL by 50 → safe step is 2 (childRows-34).
+	got := string(vr.Render([]byte("\x1b[34;10H\x1b[50E")))
 	if !strings.Contains(got, "\x1b[2E") {
-		t.Fatalf("CNL 50 from row 35 should clamp to 2: got %q", got)
+		t.Fatalf("CNL 50 from row 34 should clamp to 2: got %q", got)
 	}
 }
 

internal/harness/scenarios/canonical_output_noise.json

@@ -0,0 +1,62 @@
+{
+  "name": "canonical_output_noise",
+  "steps": [
+    {
+      "type": "mcp_call",
+      "method": "spawn_process",
+      "params": {
+        "kind": "command",
+        "argv": [
+          "sh",
+          "-lc",
+          "printf '\\033[31mStatus: running 12s\\033[0m\\nStatus: running 13s\\n╭────╮\\n│    │\\nDownloading 10%%\\rDownloading 100%%\\nFINAL: deploy ready\\n'; sleep 5"
+        ],
+        "name": "noisy"
+      },
+      "save_as": "proc"
+    },
+    {
+      "type": "wait_until_mcp",
+      "method": "get_process_output",
+      "params": {
+        "process_id": "{{proc.process_id}}",
+        "mode": "stream",
+        "raw": true,
+        "max_lines": 20
+      },
+      "path": "content",
+      "contains": "FINAL: deploy ready",
+      "timeout_ms": 5000,
+      "save_as": "raw"
+    },
+    {
+      "type": "assert_saved",
+      "from": "raw",
+      "path": "content",
+      "contains": "FINAL: deploy ready"
+    },
+    {
+      "type": "mcp_call",
+      "method": "get_process_output",
+      "params": {
+        "process_id": "{{proc.process_id}}",
+        "mode": "stream",
+        "since_offset": 0,
+        "max_lines": 20
+      },
+      "save_as": "canonical"
+    },
+    {
+      "type": "assert_saved",
+      "from": "canonical",
+      "path": "content",
+      "equals": "Status: running [time]\nDownloading [count]\nFINAL: deploy ready"
+    },
+    {
+      "type": "assert_saved",
+      "from": "canonical",
+      "path": "canonicalized",
+      "equals": true
+    }
+  ]
+}

internal/harness/scenarios/error_flash_preserves_focused_pane.json

@@ -0,0 +1,37 @@
+{
+  "name": "error_flash_preserves_focused_pane",
+  "presets": {
+    "processes": [
+      {
+        "name": "steady",
+        "argv": ["sh", "-lc", "printf 'STEADY READY\\n'; sleep 5"]
+      }
+    ]
+  },
+  "trust": ["steady"],
+  "steps": [
+    {
+      "type": "mcp_call",
+      "method": "spawn_process",
+      "params": {"kind": "command", "preset": "steady", "name": "steady"},
+      "save_as": "proc"
+    },
+    { "type": "wait_text", "contains": "STEADY READY", "timeout_ms": 5000 },
+    { "type": "send_chord", "chord": "ctrl-k" },
+    { "type": "send_text", "text": "Open Settings" },
+    { "type": "send_chord", "chord": "enter" },
+    { "type": "send_chord", "chord": "enter" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "send_chord", "chord": "enter" },
+    { "type": "wait_text", "contains": "no active top-level agent to summarize", "timeout_ms": 5000 },
+    { "type": "wait_text", "contains": "STEADY READY", "timeout_ms": 5000 },
+    { "type": "assert_contains", "contains": "STEADY READY" },
+    { "type": "assert_not_contains", "contains": "Press Ctrl-K to spawn an agent or process" }
+  ]
+}

internal/harness/scenarios/idle_screen_permission_prompt.json

@@ -0,0 +1,37 @@
+{
+  "name": "idle_screen_permission_prompt",
+  "presets": {
+    "processes": [
+      {
+        "name": "screen-permission",
+        "argv": [
+          "sh",
+          "-lc",
+          "printf '\\033[2J\\033[HCalling patterm...\\n\\nTool use\\n\\nDo you want to proceed?\\n  1. Yes\\n'; i=0; while [ $i -lt 300 ]; do printf '\\033[HCalling patterm... %03d' $i; i=$((i+1)); done; sleep 60"
+        ],
+        "idle_detection": {
+          "strategy": "output_activity",
+          "idle_threshold_ms": 500,
+          "permission_patterns": ["Do you want to proceed\\?"]
+        }
+      }
+    ]
+  },
+  "trust": ["screen-permission"],
+  "steps": [
+    {
+      "type": "mcp_call",
+      "method": "spawn_process",
+      "params": {"kind": "command", "preset": "screen-permission", "name": "screen-permission"},
+      "save_as": "proc"
+    },
+    {
+      "type": "wait_until_mcp",
+      "method": "get_process_status",
+      "params": {"process_id": "{{proc.process_id}}"},
+      "path": "idle_state",
+      "equals": "permission",
+      "timeout_ms": 4000
+    }
+  ]
+}

internal/harness/scenarios/rename_process_via_palette.json

@@ -16,7 +16,7 @@
     { "type": "send_chord", "chord": "ctrl-k" },
     { "type": "send_text", "text": "Rename process" },
     { "type": "send_chord", "chord": "enter" },
-    { "type": "wait_text", "contains": "Rename process", "timeout_ms": 3000 },
+    { "type": "wait_text", "contains": "process: original", "timeout_ms": 3000 },
     { "type": "send_chord", "chord": "ctrl-u" },
     { "type": "send_text", "text": "renamed-pane" },
     { "type": "send_chord", "chord": "enter" },

internal/harness/scenarios/restart_process_keeps_chrome.json

@@ -0,0 +1,32 @@
+{
+  "name": "restart_process_keeps_chrome",
+  "cols": 120,
+  "rows": 40,
+  "scripts": [
+    {
+      "name": "slow-restart",
+      "body": "#!/bin/sh\ncount_file=\"$XDG_RUNTIME_DIR/slow-restart-count\"\nif [ -f \"$count_file\" ]; then\n  n=$(cat \"$count_file\")\nelse\n  n=0\nfi\nn=$((n + 1))\nprintf '%s\\n' \"$n\" > \"$count_file\"\nprintf 'SLOW READY %s\\n' \"$n\"\ntrap 'sleep 3; exit 0' TERM\nwhile true; do sleep 1; done\n"
+    }
+  ],
+  "steps": [
+    {
+      "type": "mcp_call",
+      "method": "spawn_process",
+      "params": { "kind": "command", "argv": ["slow-restart"], "name": "slow-restart" },
+      "save_as": "spawned"
+    },
+    {
+      "type": "mcp_call",
+      "method": "select_process",
+      "params": { "process_id": "{{spawned.process_id}}" }
+    },
+    { "type": "wait_text", "contains": "SLOW READY 1", "timeout_ms": 5000 },
+    { "type": "wait_stable", "timeout_ms": 2000 },
+    { "type": "assert_contains", "contains": "Processes" },
+    { "type": "send_text", "text": "\u000brestart\r" },
+    { "type": "wait_stable", "timeout_ms": 2000 },
+    { "type": "assert_contains", "contains": "Processes" },
+    { "type": "assert_contains", "contains": "slow-restart" },
+    { "type": "wait_text", "contains": "SLOW READY 2", "timeout_ms": 7000 }
+  ]
+}

internal/harness/scenarios/sidebar_survives_linefeed_scroll.json

@@ -5,7 +5,7 @@
   "scripts": [
     {
       "name": "linefeed-scroll",
-      "body": "#!/bin/sh\n# Plain LF at the bottom of the child viewport scrolls the host's\n# DECSTBM region. Because that region spans every column, enough LFs\n# drag the sidebar border and section labels out of the visible region\n# unless patterm invalidates and repaints the sidebar cache.\ni=0\nwhile [ $i -lt 12 ]; do\n  printf 'warmup %02d\\n' \"$i\"\n  i=$((i + 1))\n  sleep 0.05\ndone\nprintf 'LINEFEED READY\\n'\nIFS= read -r _\nprintf '\\033[1;37r'\nprintf '\\033[37;1H'\ni=0\nwhile [ $i -lt 45 ]; do\n  printf 'scroll line %02d\\n' \"$i\"\n  i=$((i + 1))\ndone\nprintf 'LINEFEED DONE\\n'\nsleep 5\n"
+      "body": "#!/bin/sh\n# Plain LF at the bottom of the child viewport scrolls the host's\n# DECSTBM region. Because that region spans every column, enough LFs\n# drag the sidebar border and section labels out of the visible region\n# unless patterm invalidates and repaints the sidebar cache.\ni=0\nwhile [ $i -lt 12 ]; do\n  printf 'warmup %02d\\n' \"$i\"\n  i=$((i + 1))\n  sleep 0.05\ndone\nprintf 'LINEFEED READY\\n'\nIFS= read -r _\nprintf '\\033[1;36r'\nprintf '\\033[36;1H'\ni=0\nwhile [ $i -lt 45 ]; do\n  printf 'scroll line %02d\\n' \"$i\"\n  i=$((i + 1))\ndone\nprintf 'LINEFEED DONE\\n'\nsleep 5\n"
     }
   ],
   "steps": [
@@ -19,13 +19,13 @@
     { "type": "mark_raw", "save_as": "before_scroll" },
     { "type": "send_chord", "chord": "enter" },
     { "type": "wait_text", "contains": "LINEFEED DONE", "timeout_ms": 5000 },
+    { "type": "wait_stable", "timeout_ms": 2000 },
     {
       "type": "assert_raw_since_regex",
       "from": "before_scroll",
-      "regex": "Agent Tree",
+      "regex": "LINEFEED DONE",
       "timeout_ms": 2000
     },
-    { "type": "wait_stable", "timeout_ms": 2000 },
     { "type": "assert_contains", "contains": "Processes" },
     { "type": "assert_contains", "contains": "Agent Tree" },
     { "type": "assert_contains", "contains": "Scratchpads" },

internal/harness/scenarios/toast_dismiss.json

@@ -0,0 +1,32 @@
+{
+  "name": "toast_dismiss",
+  "presets": {
+    "processes": [
+      {
+        "name": "steady",
+        "argv": ["sh", "-lc", "printf 'STEADY READY\\n'; sleep 30"]
+      }
+    ]
+  },
+  "trust": ["steady"],
+  "steps": [
+    {
+      "type": "mcp_call",
+      "method": "spawn_process",
+      "params": {"kind": "command", "preset": "steady", "name": "steady"},
+      "save_as": "proc"
+    },
+    { "type": "wait_text", "contains": "STEADY READY", "timeout_ms": 5000 },
+    {
+      "type": "mcp_call",
+      "method": "request_human_attention",
+      "params": {"process_id": "{{proc.process_id}}", "reason": "needs eyes on the deploy"}
+    },
+    { "type": "wait_text", "contains": "needs eyes on the deploy", "timeout_ms": 5000 },
+    { "type": "assert_contains", "contains": "STEADY READY" },
+    { "type": "send_chord", "chord": "ctrl-n" },
+    { "type": "wait_stable", "timeout_ms": 2000 },
+    { "type": "assert_contains", "contains": "STEADY READY" },
+    { "type": "assert_not_contains", "contains": "needs eyes on the deploy" }
+  ]
+}

internal/mcp/mcp.go

@@ -96,10 +96,34 @@ func (s *Server) acceptLoop() {
 // identity token (SPEC §10); we resolve it to a child id and stash that
 // as the caller for every subsequent tool call.
 func (s *Server) handleConn(conn net.Conn) {
-	defer conn.Close()
+	var writeMu sync.Mutex
+	var wg sync.WaitGroup
+	defer func() {
+		wg.Wait()
+		_ = conn.Close()
+	}()
 	r := bufio.NewReader(conn)
 
 	var callerID string
+	writeResp := func(resp []byte) bool {
+		if resp == nil {
+			return true
+		}
+		resp = append(resp, '\n')
+		writeMu.Lock()
+		defer writeMu.Unlock()
+		for len(resp) > 0 {
+			n, err := conn.Write(resp)
+			if err != nil {
+				return false
+			}
+			if n == 0 {
+				return false
+			}
+			resp = resp[n:]
+		}
+		return true
+	}
 
 	greeting, err := r.ReadBytes('\n')
 	if err != nil {
@@ -115,24 +139,21 @@ func (s *Server) handleConn(conn net.Conn) {
 	} else {
 		// Treat as a real request from an unknown caller.
 		resp := s.dispatch("", greeting)
-		if resp != nil {
-			resp = append(resp, '\n')
-			if _, werr := conn.Write(resp); werr != nil {
-				return
-			}
+		if !writeResp(resp) {
+			return
 		}
 	}
 
 	for {
 		line, err := r.ReadBytes('\n')
 		if len(line) > 0 {
-			resp := s.dispatch(callerID, line)
-			if resp != nil {
-				resp = append(resp, '\n')
-				if _, werr := conn.Write(resp); werr != nil {
-					return
-				}
-			}
+			req := append([]byte(nil), line...)
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				resp := s.dispatch(callerID, req)
+				_ = writeResp(resp)
+			}()
 		}
 		if err != nil {
 			return

internal/mcp/mcp_test.go

@@ -0,0 +1,190 @@
+package mcp
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"net"
+	"sync"
+	"syscall"
+	"testing"
+	"time"
+
+	"github.com/hjbdev/patterm/internal/scratchpad"
+)
+
+func TestHandleConnDispatchesRequestsConcurrently(t *testing.T) {
+	serverConn, clientConn := net.Pipe()
+	t.Cleanup(func() { _ = clientConn.Close() })
+
+	host := &blockingToolHost{
+		waitEntered: make(chan struct{}),
+		waitRelease: make(chan struct{}),
+	}
+	s := &Server{}
+	s.SetHost(host)
+	done := make(chan struct{})
+	go func() {
+		s.handleConn(serverConn)
+		close(done)
+	}()
+
+	reader := bufio.NewReader(clientConn)
+	writeLine(t, clientConn, `{"patterm_identity":"ident"}`)
+	writeLine(t, clientConn, `{"jsonrpc":"2.0","id":1,"method":"wait_for_pattern","params":{"process_id":"p_slow","pattern":"never","timeout_seconds":300}}`)
+	select {
+	case <-host.waitEntered:
+	case <-time.After(time.Second):
+		t.Fatal("wait_for_pattern did not enter fake host")
+	}
+
+	writeLine(t, clientConn, `{"jsonrpc":"2.0","id":2,"method":"get_process_status","params":{"process_id":"p_fast"}}`)
+	fast := readJSONRPCResponse(t, clientConn, reader, time.Second)
+	if got := string(fast.ID); got != "2" {
+		t.Fatalf("first response id = %s, want 2; response=%s", got, fast.Raw)
+	}
+	if fast.Error != nil {
+		t.Fatalf("fast response returned error: %+v", fast.Error)
+	}
+
+	_ = clientConn.SetReadDeadline(time.Now().Add(50 * time.Millisecond))
+	if line, err := reader.ReadBytes('\n'); err == nil {
+		t.Fatalf("slow response arrived before release: %s", line)
+	}
+
+	close(host.waitRelease)
+	slow := readJSONRPCResponse(t, clientConn, reader, time.Second)
+	if got := string(slow.ID); got != "1" {
+		t.Fatalf("second response id = %s, want 1; response=%s", got, slow.Raw)
+	}
+	if slow.Error != nil {
+		t.Fatalf("slow response returned error: %+v", slow.Error)
+	}
+
+	_ = clientConn.Close()
+	select {
+	case <-done:
+	case <-time.After(time.Second):
+		t.Fatal("handleConn did not exit after client close")
+	}
+}
+
+type jsonRPCResponse struct {
+	Raw    string
+	ID     json.RawMessage    `json:"id"`
+	Result map[string]any     `json:"result"`
+	Error  *jsonRPCErrorShape `json:"error"`
+}
+
+type jsonRPCErrorShape struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+func writeLine(t *testing.T, conn net.Conn, line string) {
+	t.Helper()
+	_ = conn.SetWriteDeadline(time.Now().Add(time.Second))
+	if _, err := fmt.Fprintln(conn, line); err != nil {
+		t.Fatalf("write %s: %v", line, err)
+	}
+}
+
+func readJSONRPCResponse(t *testing.T, conn net.Conn, reader *bufio.Reader, timeout time.Duration) jsonRPCResponse {
+	t.Helper()
+	_ = conn.SetReadDeadline(time.Now().Add(timeout))
+	line, err := reader.ReadBytes('\n')
+	if err != nil {
+		t.Fatalf("read response: %v", err)
+	}
+	var resp jsonRPCResponse
+	resp.Raw = string(line)
+	if err := json.Unmarshal(line, &resp); err != nil {
+		t.Fatalf("parse response %s: %v", line, err)
+	}
+	return resp
+}
+
+type blockingToolHost struct {
+	waitEntered chan struct{}
+	waitRelease chan struct{}
+	waitOnce    sync.Once
+}
+
+func (h *blockingToolHost) ResolveCallerIdentity(identity string) string { return "caller-" + identity }
+func (h *blockingToolHost) CallerRole(string) CallerRole                 { return RoleOrchestrator }
+func (h *blockingToolHost) SpawnAgent(string, SpawnAgentArgs) (ProcessInfo, error) {
+	return ProcessInfo{}, nil
+}
+func (h *blockingToolHost) SpawnProcess(string, SpawnProcessArgs) (ProcessInfo, error) {
+	return ProcessInfo{}, nil
+}
+func (h *blockingToolHost) StartProcess(string, string) (ProcessInfo, error) {
+	return ProcessInfo{}, nil
+}
+func (h *blockingToolHost) RestartProcess(string, string, syscall.Signal) (ProcessInfo, error) {
+	return ProcessInfo{}, nil
+}
+func (h *blockingToolHost) StopProcess(string, string, syscall.Signal) (ProcessInfo, error) {
+	return ProcessInfo{}, nil
+}
+func (h *blockingToolHost) CloseProcess(string, string) error          { return nil }
+func (h *blockingToolHost) RenameProcess(string, string, string) error { return nil }
+func (h *blockingToolHost) SelectProcess(string, string) error         { return nil }
+func (h *blockingToolHost) ListProcesses(string, string) []ProcessInfo { return nil }
+func (h *blockingToolHost) GetProcessStatus(string, string) (ProcessStatus, error) {
+	return ProcessStatus{ProcessInfo: ProcessInfo{ID: "p_fast", Status: "running"}}, nil
+}
+func (h *blockingToolHost) GetProjectStatus(string, bool) (ProjectStatus, error) {
+	return ProjectStatus{}, nil
+}
+func (h *blockingToolHost) GetProcessOutput(string, ProcessOutputArgs) (ProcessOutput, error) {
+	return ProcessOutput{}, nil
+}
+func (h *blockingToolHost) GetProcessRawOutput(string, RawOutputArgs) (RawOutput, error) {
+	return RawOutput{}, nil
+}
+func (h *blockingToolHost) SearchOutput(string, SearchOutputArgs) (SearchResult, error) {
+	return SearchResult{}, nil
+}
+func (h *blockingToolHost) WaitForPattern(string, string, string, float64, string) (bool, string, error) {
+	h.waitOnce.Do(func() { close(h.waitEntered) })
+	<-h.waitRelease
+	return true, "matched", nil
+}
+func (h *blockingToolHost) GetProcessPorts(string, string) ([]PortSighting, error) {
+	return nil, nil
+}
+func (h *blockingToolHost) SendInput(string, SendInputArgs) (SendInputResult, error) {
+	return SendInputResult{}, nil
+}
+func (h *blockingToolHost) SendMessage(string, string, string) error           { return nil }
+func (h *blockingToolHost) RequestHumanAttention(string, string, string) error { return nil }
+func (h *blockingToolHost) TimerWait(string, float64, string) (string, error) {
+	return "", nil
+}
+func (h *blockingToolHost) TimerSet(string, TimerSetArgs) (TimerHandle, error) {
+	return TimerHandle{}, nil
+}
+func (h *blockingToolHost) TimerFireWhenIdleAny(string, TimerFireWhenIdleArgs) (TimerFireWhenIdleResponse, error) {
+	return TimerFireWhenIdleResponse{}, nil
+}
+func (h *blockingToolHost) TimerFireWhenIdleAll(string, TimerFireWhenIdleArgs) (TimerFireWhenIdleResponse, error) {
+	return TimerFireWhenIdleResponse{}, nil
+}
+func (h *blockingToolHost) TimerCancel(string, string) error { return nil }
+func (h *blockingToolHost) TimerPause(string, string) error  { return nil }
+func (h *blockingToolHost) TimerResume(string, string) error { return nil }
+func (h *blockingToolHost) TimerList(string) ([]TimerInfo, error) {
+	return nil, nil
+}
+func (h *blockingToolHost) ScratchpadList() ([]scratchpad.Entry, error) { return nil, nil }
+func (h *blockingToolHost) ScratchpadRead(ScratchpadReadArgs) (ScratchpadReadResult, error) {
+	return ScratchpadReadResult{}, nil
+}
+func (h *blockingToolHost) ScratchpadWrite(string, string, string) (string, error) {
+	return "", nil
+}
+func (h *blockingToolHost) ScratchpadAppend(string, string) error { return nil }
+func (h *blockingToolHost) ScratchpadDelete(string) error         { return nil }
+func (h *blockingToolHost) WhoAmI(string, bool) WhoAmI            { return WhoAmI{} }
+func (h *blockingToolHost) Help(string, string) HelpResponse      { return HelpResponse{} }

internal/mcp/protocol.go

@@ -3,6 +3,8 @@ package mcp
 import (
 	"encoding/json"
 	"fmt"
+
+	"github.com/hjbdev/patterm/internal/scratchpad"
 )
 
 // MCP protocol surface. The patterm server originally exposed each
@@ -27,6 +29,24 @@ var serverInfo = map[string]any{
 	"version": "0.1.0",
 }
 
+// serverInstructions is returned in the MCP `initialize` response. MCP
+// clients show this to the underlying LLM as context for how to use
+// the server. Failure modes we've seen and want to head off:
+//   - The agent assumes patterm is something it has to launch (running
+//     `patterm` or `patterm mcp-stdio` from its own shell). It's
+//     already attached — it just calls the tools.
+//   - The agent reaches for shell tools (perl / nc / socat / curl) to
+//     poke patterm's Unix socket directly. That socket connection
+//     carries no caller identity, so any sub-agent the agent spawns
+//     that way ends up as a stray top-level tab instead of a child
+//     under the spawning agent. Always go through the MCP tools.
+//   - The agent shells out to `claude` / `codex` / `opencode` to start
+//     a peer instead of calling `spawn_agent`. Those peers won't show
+//     up as sub-agents and won't be tied into the patterm lifecycle.
+//
+// Keep this short — clients vary in how much they surface to the LLM.
+const serverInstructions = "You are inside patterm. Use these MCP tools; do not launch patterm or poke its Unix socket yourself. Use spawn_agent for sub-agents, close spawned panes when done, and use timer_fire_when_idle_* instead of wait_for_pattern to wait for send_message replies."
+
 // toolDescriptor is the shape returned by `tools/list`. inputSchema is
 // a JSON Schema object — we provide a minimal `{type: "object"}` schema
 // for each tool, which lets MCP clients accept arbitrary arguments and
@@ -58,37 +78,41 @@ func objectSchema(properties map[string]any, required []string) map[string]any {
 }
 
 func stringProp(desc string) map[string]any {
-	return map[string]any{"type": "string", "description": desc}
+	_ = desc
+	return map[string]any{"type": "string"}
 }
 
 func numberProp(desc string) map[string]any {
-	return map[string]any{"type": "number", "description": desc}
+	_ = desc
+	return map[string]any{"type": "number"}
 }
 
 func integerProp(desc string) map[string]any {
-	return map[string]any{"type": "integer", "description": desc}
+	_ = desc
+	return map[string]any{"type": "integer"}
 }
 
 func booleanProp(desc string) map[string]any {
-	return map[string]any{"type": "boolean", "description": desc}
+	_ = desc
+	return map[string]any{"type": "boolean"}
 }
 
 func arrayOfStringsProp(desc string) map[string]any {
+	_ = desc
 	return map[string]any{
-		"type":        "array",
-		"description": desc,
-		"items":       map[string]any{"type": "string"},
+		"type":  "array",
+		"items": map[string]any{"type": "string"},
 	}
 }
 
 // toolCatalog is the full list advertised via tools/list. Descriptions
 // are intentionally short — clients are expected to fetch help() for
 // detail. Schemas mirror the param structs in tools.go.
-func toolCatalog() []toolDescriptor {
-	return []toolDescriptor{
+func toolCatalog(role CallerRole) []toolDescriptor {
+	tools := []toolDescriptor{
 		{
 			Name:        "spawn_agent",
-			Description: "Spawn a sub-agent from an agent preset and optionally seed it with initial instructions. Caller owns lifecycle: when the sub-agent's work is done (it reports back via send_message, or you no longer need it), call close_process on its process_id to free the pane and tear down the PTY. See help('lifecycle').",
+			Description: "Spawn a sub-agent from an agent preset.",
 			InputSchema: objectSchema(map[string]any{
 				"agent":              stringProp("Preset name (e.g. \"claude\", \"codex\")."),
 				"agent_instructions": stringProp("Initial prompt typed into the agent after it's ready."),
@@ -97,14 +121,14 @@ func toolCatalog() []toolDescriptor {
 		},
 		{
 			Name:        "spawn_process",
-			Description: "Spawn a process: a terminal, a process preset, or a freeform argv command. Caller owns lifecycle: when the process is no longer needed, call close_process to remove its entry (live children are SIGKILL'd first). See help('lifecycle').",
+			Description: "Spawn a terminal, process preset, or argv command.",
 			InputSchema: objectSchema(map[string]any{
 				"kind":        stringProp("\"terminal\" or \"command\"."),
 				"preset":      stringProp("Process preset name (mutually exclusive with argv)."),
-				"argv":        map[string]any{"type": "array", "items": map[string]any{"type": "string"}, "description": "Argv vector for freeform commands."},
+				"argv":        map[string]any{"type": "array", "items": map[string]any{"type": "string"}},
 				"name":        stringProp("Display name for the pane."),
 				"working_dir": stringProp("Working directory for the spawned process."),
-				"env":         map[string]any{"type": "object", "additionalProperties": map[string]any{"type": "string"}, "description": "Extra environment variables."},
+				"env":         map[string]any{"type": "object", "additionalProperties": map[string]any{"type": "string"}},
 				"shell":       booleanProp("Run argv through sh -lc."),
 			}, nil),
 		},
@@ -170,23 +194,30 @@ func toolCatalog() []toolDescriptor {
 		{
 			Name:        "get_project_status",
 			Description: "One-shot orientation: project, caller, processes, scratchpads.",
-			InputSchema: objectSchema(nil, nil),
+			InputSchema: objectSchema(map[string]any{
+				"include_tools": booleanProp("Include available_tools in caller metadata."),
+			}, nil),
 		},
 		{
 			Name:        "get_process_output",
-			Description: "Read rendered grid (\"grid\") or ANSI-stripped stream (\"stream\") output, with screen-version watermark.",
+			Description: "Read canonical terminal text by default: visible grid (\"grid\") or recent stream (\"stream\") with ANSI/control noise, borders, duplicate status churn, and volatile timers removed. Set raw=true only for diagnostic ANSI-preserved PTY bytes.",
 			InputSchema: objectSchema(map[string]any{
 				"process_id":   stringProp("Target process id."),
 				"mode":         stringProp("\"grid\" (default) or \"stream\"."),
 				"since_offset": integerProp("Watermark offset from a previous call."),
+				"max_bytes":    integerProp("Maximum content bytes to return."),
+				"max_lines":    integerProp("Maximum canonical lines to return (default 120, max 500)."),
+				"raw":          booleanProp("Return raw ANSI-preserved stream bytes instead of canonical text."),
+				"include_meta": booleanProp("Include verbose cursor, geometry, active screen, idle, and screen-version metadata."),
 			}, []string{"process_id"}),
 		},
 		{
 			Name:        "get_process_raw_output",
-			Description: "Read the raw ANSI byte stream since since_offset.",
+			Description: "Compatibility alias for raw=true get_process_output: read the raw ANSI byte stream since since_offset.",
 			InputSchema: objectSchema(map[string]any{
 				"process_id":   stringProp("Target process id."),
 				"since_offset": integerProp("Byte offset from a previous call."),
+				"max_bytes":    integerProp("Maximum content bytes to return."),
 			}, []string{"process_id"}),
 		},
 		{
@@ -196,12 +227,13 @@ func toolCatalog() []toolDescriptor {
 				"process_id": stringProp("Target process id."),
 				"pattern":    stringProp("Regex pattern."),
 				"kind":       stringProp("\"rendered\" (default) or \"raw\"."),
-				"limit":      integerProp("Max matches (default 20)."),
+				"limit":      integerProp("Max matches (default 10)."),
+				"max_bytes":  integerProp("Max bytes per returned match line."),
 			}, []string{"process_id", "pattern"}),
 		},
 		{
 			Name:        "wait_for_pattern",
-			Description: "Block until pattern appears in process output or timeout elapses.",
+			Description: "Block until pattern appears in the target process output.",
 			InputSchema: objectSchema(map[string]any{
 				"process_id":      stringProp("Target process id."),
 				"pattern":         stringProp("Regex pattern."),
@@ -220,18 +252,19 @@ func toolCatalog() []toolDescriptor {
 			Name:        "send_input",
 			Description: "Type text, paste a block, or fire a named key into a process. Optional tail-after-send.",
 			InputSchema: objectSchema(map[string]any{
-				"process_id": stringProp("Target process id."),
-				"kind":       stringProp("\"text\", \"paste\", or \"key\"."),
-				"text":       stringProp("Text payload for kind=text/paste."),
-				"key":        stringProp("Named key for kind=key (e.g. \"enter\", \"escape\")."),
-				"submit":     booleanProp("Whether to append a submit keystroke."),
-				"wait_ms":    integerProp("After sending, wait this many ms before tailing."),
-				"tail_mode":  stringProp("\"none\" (default), \"stream\", or \"grid\"."),
+				"process_id":     stringProp("Target process id."),
+				"kind":           stringProp("\"text\", \"paste\", or \"key\"."),
+				"text":           stringProp("Text payload for kind=text/paste."),
+				"key":            stringProp("Named key for kind=key (e.g. \"enter\", \"escape\")."),
+				"submit":         booleanProp("Whether to append a submit keystroke."),
+				"wait_ms":        integerProp("After sending, wait this many ms before tailing."),
+				"tail_mode":      stringProp("\"none\" (default), \"stream\", or \"grid\"."),
+				"tail_max_bytes": integerProp("Maximum bytes in returned tail."),
 			}, []string{"process_id", "kind"}),
 		},
 		{
 			Name:        "send_message",
-			Description: "Deliver a text message to another process as orchestrator-owned input.",
+			Description: "Send a tagged message to a parent or child process.",
 			InputSchema: objectSchema(map[string]any{
 				"target_process_id": stringProp("Recipient process id."),
 				"message":           stringProp("Message body."),
@@ -265,7 +298,7 @@ func toolCatalog() []toolDescriptor {
 		},
 		{
 			Name:        "timer_fire_when_idle_any",
-			Description: "Schedule a timer that fires when any watched process enters idle (already-idle entries excluded), or when max_wait_seconds elapses.",
+			Description: "Fire when any watched process becomes idle.",
 			InputSchema: objectSchema(map[string]any{
 				"watched":          arrayOfStringsProp("Process ids to watch."),
 				"body":             stringProp("Message delivered verbatim to the owning agent when the timer fires."),
@@ -276,7 +309,7 @@ func toolCatalog() []toolDescriptor {
 		},
 		{
 			Name:        "timer_fire_when_idle_all",
-			Description: "Schedule a timer that fires when all watched processes are idle (already-idle entries count as satisfied), or when max_wait_seconds elapses.",
+			Description: "Fire when all watched processes are idle.",
 			InputSchema: objectSchema(map[string]any{
 				"watched":          arrayOfStringsProp("Process ids to watch."),
 				"body":             stringProp("Message delivered verbatim to the owning agent when the timer fires."),
@@ -320,7 +353,9 @@ func toolCatalog() []toolDescriptor {
 			Name:        "scratchpad_read",
 			Description: "Read a scratchpad entry, returning content and revision.",
 			InputSchema: objectSchema(map[string]any{
-				"name": stringProp("Scratchpad name."),
+				"name":      stringProp("Scratchpad name."),
+				"offset":    integerProp("Byte offset to start reading."),
+				"max_bytes": integerProp("Maximum content bytes to return."),
 			}, []string{"name"}),
 		},
 		{
@@ -340,10 +375,19 @@ func toolCatalog() []toolDescriptor {
 				"content": stringProp("Text to append."),
 			}, []string{"name", "content"}),
 		},
+		{
+			Name:        "scratchpad_delete",
+			Description: "Delete a scratchpad entry.",
+			InputSchema: objectSchema(map[string]any{
+				"name": stringProp("Scratchpad name."),
+			}, []string{"name"}),
+		},
 		{
 			Name:        "whoami",
-			Description: "Return the caller's identity, role, parent, project metadata, and available tools.",
-			InputSchema: objectSchema(nil, nil),
+			Description: "Return caller identity, role, parent, and project metadata.",
+			InputSchema: objectSchema(map[string]any{
+				"include_tools": booleanProp("Include full available tool list."),
+			}, nil),
 		},
 		{
 			Name:        "help",
@@ -353,6 +397,16 @@ func toolCatalog() []toolDescriptor {
 			}, nil),
 		},
 	}
+	if role != RoleSubAgent {
+		return tools
+	}
+	filtered := tools[:0]
+	for _, tool := range tools {
+		if tool.Name != "spawn_agent" {
+			filtered = append(filtered, tool)
+		}
+	}
+	return filtered
 }
 
 // handleProtocolMethod handles MCP protocol-level methods. Returns
@@ -377,7 +431,8 @@ func (s *Server) handleProtocolMethod(callerID, method string, params json.RawMe
 			"capabilities": map[string]any{
 				"tools": map[string]any{"listChanged": false},
 			},
-			"serverInfo": serverInfo,
+			"serverInfo":   serverInfo,
+			"instructions": serverInstructions,
 		}
 		return result, true, 0, "", nil
 
@@ -390,7 +445,14 @@ func (s *Server) handleProtocolMethod(callerID, method string, params json.RawMe
 		return map[string]any{}, true, 0, "", nil
 
 	case "tools/list":
-		return map[string]any{"tools": toolCatalog()}, true, 0, "", nil
+		role := RoleOrchestrator
+		s.mu.Lock()
+		host := s.host
+		s.mu.Unlock()
+		if host != nil {
+			role = host.CallerRole(callerID)
+		}
+		return map[string]any{"tools": toolCatalog(role)}, true, 0, "", nil
 
 	case "tools/call":
 		var p struct {
@@ -446,25 +508,12 @@ func (s *Server) handleProtocolMethod(callerID, method string, params json.RawMe
 	return nil, false, 0, "", nil
 }
 
-// wrapToolResult turns a structured tool result into an MCP tools/call
-// response. Plain strings (e.g. "ok") become text content; structured
-// values are JSON-encoded into a single text block and also exposed
-// under structuredContent so capable clients can read the shape.
+// wrapToolResult turns a tool result into an MCP tools/call response.
+// Structured values are exposed once under structuredContent; content
+// carries only a short model-readable summary to avoid duplicating
+// large JSON payloads into the transcript.
 func wrapToolResult(result any) map[string]any {
-	var text string
-	switch v := result.(type) {
-	case nil:
-		text = "ok"
-	case string:
-		text = v
-	default:
-		b, err := json.Marshal(v)
-		if err != nil {
-			text = fmt.Sprintf("%v", v)
-		} else {
-			text = string(b)
-		}
-	}
+	text := summarizeToolResult(result)
 	out := map[string]any{
 		"content": []map[string]any{{"type": "text", "text": text}},
 		"isError": false,
@@ -479,3 +528,70 @@ func wrapToolResult(result any) map[string]any {
 	}
 	return out
 }
+
+func summarizeToolResult(result any) string {
+	switch v := result.(type) {
+	case nil:
+		return "ok"
+	case string:
+		return v
+	case ProcessInfo:
+		return fmt.Sprintf("%s %s %s", v.ID, v.Kind, v.Status)
+	case []ProcessInfo:
+		return fmt.Sprintf("%d processes", len(v))
+	case ProcessStatus:
+		return fmt.Sprintf("%s %s %s", v.ID, v.Kind, v.Status)
+	case ProjectStatus:
+		return fmt.Sprintf("%d processes, %d scratchpads", len(v.Processes), len(v.Scratchpads))
+	case ProcessOutput:
+		return outputSummary(v.Mode, v.ContentBytes, v.Truncated, v.NewOffset)
+	case RawOutput:
+		return outputSummary("raw", v.ContentBytes, v.Truncated, v.NewOffset)
+	case SearchResult:
+		if v.Truncated {
+			return fmt.Sprintf("%d matches (truncated)", len(v.Matches))
+		}
+		return fmt.Sprintf("%d matches", len(v.Matches))
+	case SendInputResult:
+		if v.Tail != nil {
+			return "ok; tail included"
+		}
+		return "ok"
+	case TimerHandle:
+		return "timer " + v.ID
+	case TimerFireWhenIdleResponse:
+		if v.ID != "" {
+			return fmt.Sprintf("%s timer %s", v.Status, v.ID)
+		}
+		return v.Status
+	case []TimerInfo:
+		return fmt.Sprintf("%d timers", len(v))
+	case []scratchpad.Entry:
+		return fmt.Sprintf("%d scratchpads", len(v))
+	case ScratchpadReadResult:
+		if v.Truncated {
+			return fmt.Sprintf("%d/%d bytes from offset %d", v.ContentBytes, v.TotalBytes, v.Offset)
+		}
+		return fmt.Sprintf("%d bytes", v.ContentBytes)
+	case WhoAmI:
+		if v.ProcessID == "" {
+			return string(v.Role)
+		}
+		return fmt.Sprintf("%s %s", v.ProcessID, v.Role)
+	case HelpResponse:
+		return fmt.Sprintf("help: %s", v.Topic)
+	default:
+		return "ok"
+	}
+}
+
+func outputSummary(mode string, bytes int, truncated bool, offset int64) string {
+	s := fmt.Sprintf("%s output: %d bytes", mode, bytes)
+	if offset > 0 {
+		s += fmt.Sprintf(", offset %d", offset)
+	}
+	if truncated {
+		s += " (truncated)"
+	}
+	return s
+}

internal/mcp/protocol_test.go

@@ -2,6 +2,7 @@ package mcp
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 )
 
@@ -36,6 +37,16 @@ func TestInitializeReturnsCapabilities(t *testing.T) {
 	if caps["tools"] == nil {
 		t.Fatalf("tools capability missing: %+v", caps)
 	}
+	// patterm-specific orientation: clients show this to the underlying
+	// LLM, so it's our primary hook for steering vendor TUIs (codex in
+	// particular) toward the MCP tool surface instead of shell-ing out.
+	instructions, ok := parsed.Result["instructions"].(string)
+	if !ok || instructions == "" {
+		t.Fatalf("instructions missing or wrong type: %+v", parsed.Result)
+	}
+	if len(instructions) > 320 {
+		t.Fatalf("instructions too verbose: %d chars", len(instructions))
+	}
 }
 
 func TestInitializedNotificationSuppressesResponse(t *testing.T) {
@@ -67,6 +78,9 @@ func TestToolsListReturnsConcreteSchemas(t *testing.T) {
 	if parsed.Error != nil {
 		t.Fatalf("tools/list returned error: %+v", parsed.Error)
 	}
+	if len(resp) > 12000 {
+		t.Fatalf("tools/list response too large: %d bytes", len(resp))
+	}
 	tools, ok := parsed.Result["tools"].([]interface{})
 	if !ok {
 		t.Fatalf("tools not array: %+v", parsed.Result)
@@ -105,6 +119,27 @@ func TestToolsListReturnsConcreteSchemas(t *testing.T) {
 	}
 }
 
+func TestWrapToolResultDoesNotDuplicateStructuredJSON(t *testing.T) {
+	result := ProcessOutput{
+		Content:      strings.Repeat("x", 1024),
+		Mode:         "stream",
+		NewOffset:    2048,
+		ContentBytes: 1024,
+	}
+	wrapped := wrapToolResult(result)
+	if wrapped["structuredContent"] == nil {
+		t.Fatalf("structuredContent missing: %#v", wrapped)
+	}
+	content := wrapped["content"].([]map[string]any)
+	text := content[0]["text"].(string)
+	if strings.Contains(text, result.Content) {
+		t.Fatalf("content duplicated structured payload: %q", text)
+	}
+	if !strings.Contains(text, "stream output") {
+		t.Fatalf("summary text should identify output, got %q", text)
+	}
+}
+
 func TestPingReturnsEmptyObject(t *testing.T) {
 	s := &Server{}
 	req := []byte(`{"jsonrpc":"2.0","id":3,"method":"ping"}`)

internal/mcp/tools.go

@@ -74,10 +74,10 @@ type ToolHost interface {
 	// Inspection.
 	ListProcesses(callerID, kindFilter string) []ProcessInfo
 	GetProcessStatus(callerID, processID string) (ProcessStatus, error)
-	GetProjectStatus(callerID string) (ProjectStatus, error)
-	GetProcessOutput(callerID, processID, mode string, sinceOffset int64) (ProcessOutput, error)
-	GetProcessRawOutput(callerID, processID string, sinceOffset int64) (RawOutput, error)
-	SearchOutput(callerID, processID, pattern, kind string, limit int) (SearchResult, error)
+	GetProjectStatus(callerID string, includeTools bool) (ProjectStatus, error)
+	GetProcessOutput(callerID string, args ProcessOutputArgs) (ProcessOutput, error)
+	GetProcessRawOutput(callerID string, args RawOutputArgs) (RawOutput, error)
+	SearchOutput(callerID string, args SearchOutputArgs) (SearchResult, error)
 	WaitForPattern(callerID, processID, pattern string, timeoutSeconds float64, scope string) (matched bool, snippet string, err error)
 	GetProcessPorts(callerID, processID string) ([]PortSighting, error)
 
@@ -98,12 +98,13 @@ type ToolHost interface {
 
 	// Scratchpads.
 	ScratchpadList() ([]scratchpad.Entry, error)
-	ScratchpadRead(name string) (content string, revision string, err error)
+	ScratchpadRead(args ScratchpadReadArgs) (ScratchpadReadResult, error)
 	ScratchpadWrite(name, content, expectedRevision string) (revision string, err error)
 	ScratchpadAppend(name, content string) error
+	ScratchpadDelete(name string) error
 
 	// Meta.
-	WhoAmI(callerID string) WhoAmI
+	WhoAmI(callerID string, includeTools bool) WhoAmI
 	Help(callerID, topic string) HelpResponse
 }
 
@@ -156,32 +157,60 @@ type ProjectStatus struct {
 	Scratchpads []scratchpad.Entry `json:"scratchpads"`
 }
 
+type ProjectStatusArgs struct {
+	IncludeTools bool `json:"include_tools"`
+}
+
 // ProjectMeta is the project root info echoed in many payloads.
 type ProjectMeta struct {
 	Path string `json:"path"`
 	Key  string `json:"key"`
 }
 
-// ProcessOutput is the get_process_output payload. SPEC §7 enriches
-// the old read_output result with screen geometry + version.
+// ProcessOutput is the get_process_output payload. By default it is
+// canonical text with light metadata; include_meta restores screen
+// geometry + version, and raw requests return stream bytes.
 type ProcessOutput struct {
-	Content       string `json:"content"`
-	Mode          string `json:"mode"`
-	NewOffset     int64  `json:"new_offset,omitempty"`
-	ActiveScreen  string `json:"active_screen,omitempty"`
-	Rows          int    `json:"rows,omitempty"`
-	Cols          int    `json:"cols,omitempty"`
-	Cursor        Cursor `json:"cursor"`
-	IdleMS        int64  `json:"idle_ms,omitempty"`
-	Status        string `json:"status,omitempty"`
-	ScreenVersion int64  `json:"screen_version,omitempty"`
+	Content        string  `json:"content"`
+	Mode           string  `json:"mode"`
+	NewOffset      int64   `json:"new_offset,omitempty"`
+	ActiveScreen   string  `json:"active_screen,omitempty"`
+	Rows           int     `json:"rows,omitempty"`
+	Cols           int     `json:"cols,omitempty"`
+	Cursor         *Cursor `json:"cursor,omitempty"`
+	IdleMS         int64   `json:"idle_ms,omitempty"`
+	Status         string  `json:"status,omitempty"`
+	ScreenVersion  int64   `json:"screen_version,omitempty"`
+	ContentBytes   int     `json:"content_bytes,omitempty"`
+	Truncated      bool    `json:"truncated,omitempty"`
+	TruncatedBytes int     `json:"truncated_bytes,omitempty"`
+	Canonicalized  bool    `json:"canonicalized,omitempty"`
+}
+
+type ProcessOutputArgs struct {
+	ProcessID   string `json:"process_id"`
+	Mode        string `json:"mode"`
+	SinceOffset int64  `json:"since_offset"`
+	MaxBytes    int    `json:"max_bytes"`
+	MaxLines    int    `json:"max_lines"`
+	Raw         bool   `json:"raw"`
+	IncludeMeta bool   `json:"include_meta"`
 }
 
 // RawOutput is the get_process_raw_output payload — ANSI preserved.
 type RawOutput struct {
-	Content   string `json:"content"`
-	NewOffset int64  `json:"new_offset"`
-	Status    string `json:"status,omitempty"`
+	Content        string `json:"content"`
+	NewOffset      int64  `json:"new_offset"`
+	Status         string `json:"status,omitempty"`
+	ContentBytes   int    `json:"content_bytes,omitempty"`
+	Truncated      bool   `json:"truncated,omitempty"`
+	TruncatedBytes int    `json:"truncated_bytes,omitempty"`
+}
+
+type RawOutputArgs struct {
+	ProcessID   string `json:"process_id"`
+	SinceOffset int64  `json:"since_offset"`
+	MaxBytes    int    `json:"max_bytes"`
 }
 
 // SearchResult is search_output's payload.
@@ -190,6 +219,14 @@ type SearchResult struct {
 	Truncated bool          `json:"truncated"`
 }
 
+type SearchOutputArgs struct {
+	ProcessID string `json:"process_id"`
+	Pattern   string `json:"pattern"`
+	Kind      string `json:"kind"`
+	Limit     int    `json:"limit"`
+	MaxBytes  int    `json:"max_bytes"`
+}
+
 type SearchMatch struct {
 	LineNo int    `json:"line_no"`
 	Text   string `json:"text"`
@@ -244,8 +281,9 @@ type TimerInfo struct {
 	ID                string   `json:"timer_id"`
 	Label             string   `json:"label,omitempty"`
 	Body              string   `json:"body,omitempty"`
-	Kind              string   `json:"kind"`             // "delay" | "idle_any" | "idle_all"
-	Status            string   `json:"status"`           // "pending" | "paused"
+	BodyTruncated     bool     `json:"body_truncated,omitempty"`
+	Kind              string   `json:"kind"`   // "delay" | "idle_any" | "idle_all"
+	Status            string   `json:"status"` // "pending" | "paused"
 	OwnerID           string   `json:"owner_process_id"`
 	WatchedIDs        []string `json:"watched,omitempty"`
 	FiresAtUnixMS     int64    `json:"fires_at_unix_ms,omitempty"`
@@ -280,13 +318,14 @@ type SpawnProcessArgs struct {
 // SendInputArgs is the input shape for send_input — covers text /
 // paste / key with the optional wait+tail tail-after-send.
 type SendInputArgs struct {
-	ProcessID string `json:"process_id"`
-	Kind      string `json:"kind"` // "text" | "paste" | "key"
-	Text      string `json:"text"`
-	Key       string `json:"key"`
-	Submit    *bool  `json:"submit"`
-	WaitMS    int    `json:"wait_ms"`
-	TailMode  string `json:"tail_mode"` // "none" | "stream" | "grid"
+	ProcessID    string `json:"process_id"`
+	Kind         string `json:"kind"` // "text" | "paste" | "key"
+	Text         string `json:"text"`
+	Key          string `json:"key"`
+	Submit       *bool  `json:"submit"`
+	WaitMS       int    `json:"wait_ms"`
+	TailMode     string `json:"tail_mode"` // "none" | "stream" | "grid"
+	TailMaxBytes int    `json:"tail_max_bytes"`
 }
 
 // SendInputResult is the return shape of send_input.
@@ -305,6 +344,27 @@ type WhoAmI struct {
 	AvailableTools  []string    `json:"available_tools"`
 }
 
+type WhoAmIArgs struct {
+	IncludeTools bool `json:"include_tools"`
+}
+
+type ScratchpadReadArgs struct {
+	Name     string `json:"name"`
+	Offset   int    `json:"offset"`
+	MaxBytes int    `json:"max_bytes"`
+}
+
+type ScratchpadReadResult struct {
+	Content        string `json:"content"`
+	Revision       string `json:"revision"`
+	Offset         int    `json:"offset,omitempty"`
+	NextOffset     int    `json:"next_offset,omitempty"`
+	ContentBytes   int    `json:"content_bytes,omitempty"`
+	TotalBytes     int    `json:"total_bytes,omitempty"`
+	Truncated      bool   `json:"truncated,omitempty"`
+	TruncatedBytes int    `json:"truncated_bytes,omitempty"`
+}
+
 // HelpResponse is the help return shape.
 type HelpResponse struct {
 	Topic        string   `json:"topic"`
@@ -506,61 +566,51 @@ func callTool(h ToolHost, callerID, method string, params json.RawMessage) (any,
 		return st, 0, "", nil
 
 	case "get_project_status":
-		ps, err := h.GetProjectStatus(callerID)
+		var p ProjectStatusArgs
+		_ = unmarshalParamsOptional(params, &p)
+		ps, err := h.GetProjectStatus(callerID, p.IncludeTools)
 		if err != nil {
 			return mapToolError(err)
 		}
 		return ps, 0, "", nil
 
 	case "get_process_output":
-		var p struct {
-			ProcessID   string `json:"process_id"`
-			Mode        string `json:"mode"`
-			SinceOffset int64  `json:"since_offset"`
-		}
+		var p ProcessOutputArgs
 		if err := unmarshalParams(params, &p); err != nil {
 			return nil, codeInvalidParams, err.Error(), nil
 		}
 		if p.Mode == "" {
 			p.Mode = "grid"
 		}
-		out, err := h.GetProcessOutput(callerID, p.ProcessID, p.Mode, p.SinceOffset)
+		out, err := h.GetProcessOutput(callerID, p)
 		if err != nil {
 			return mapToolError(err)
 		}
 		return out, 0, "", nil
 
 	case "get_process_raw_output":
-		var p struct {
-			ProcessID   string `json:"process_id"`
-			SinceOffset int64  `json:"since_offset"`
-		}
+		var p RawOutputArgs
 		if err := unmarshalParams(params, &p); err != nil {
 			return nil, codeInvalidParams, err.Error(), nil
 		}
-		out, err := h.GetProcessRawOutput(callerID, p.ProcessID, p.SinceOffset)
+		out, err := h.GetProcessRawOutput(callerID, p)
 		if err != nil {
 			return mapToolError(err)
 		}
 		return out, 0, "", nil
 
 	case "search_output":
-		var p struct {
-			ProcessID string `json:"process_id"`
-			Pattern   string `json:"pattern"`
-			Kind      string `json:"kind"`
-			Limit     int    `json:"limit"`
-		}
+		var p SearchOutputArgs
 		if err := unmarshalParams(params, &p); err != nil {
 			return nil, codeInvalidParams, err.Error(), nil
 		}
 		if p.Limit <= 0 {
-			p.Limit = 20
+			p.Limit = 10
 		}
 		if p.Kind == "" {
 			p.Kind = "rendered"
 		}
-		res, err := h.SearchOutput(callerID, p.ProcessID, p.Pattern, p.Kind, p.Limit)
+		res, err := h.SearchOutput(callerID, p)
 		if err != nil {
 			return mapToolError(err)
 		}
@@ -730,17 +780,15 @@ func callTool(h ToolHost, callerID, method string, params json.RawMessage) (any,
 		return entries, 0, "", nil
 
 	case "scratchpad_read":
-		var p struct {
-			Name string `json:"name"`
-		}
+		var p ScratchpadReadArgs
 		if err := unmarshalParams(params, &p); err != nil {
 			return nil, codeInvalidParams, err.Error(), nil
 		}
-		content, rev, err := h.ScratchpadRead(p.Name)
+		res, err := h.ScratchpadRead(p)
 		if err != nil {
 			return nil, codeInternal, err.Error(), nil
 		}
-		return map[string]any{"content": content, "revision": rev}, 0, "", nil
+		return res, 0, "", nil
 
 	case "scratchpad_write":
 		var p struct {
@@ -776,8 +824,22 @@ func callTool(h ToolHost, callerID, method string, params json.RawMessage) (any,
 		}
 		return map[string]any{"ok": true}, 0, "", nil
 
+	case "scratchpad_delete":
+		var p struct {
+			Name string `json:"name"`
+		}
+		if err := unmarshalParams(params, &p); err != nil {
+			return nil, codeInvalidParams, err.Error(), nil
+		}
+		if err := h.ScratchpadDelete(p.Name); err != nil {
+			return nil, codeInternal, err.Error(), nil
+		}
+		return map[string]any{"ok": true}, 0, "", nil
+
 	case "whoami":
-		return h.WhoAmI(callerID), 0, "", nil
+		var p WhoAmIArgs
+		_ = unmarshalParamsOptional(params, &p)
+		return h.WhoAmI(callerID, p.IncludeTools), 0, "", nil
 
 	case "help":
 		var p struct {

internal/preset/preset.go

@@ -4,6 +4,7 @@
 package preset
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -35,15 +36,16 @@ type Preset struct {
 	Argv       []string          `json:"argv"`
 	Env        map[string]string `json:"env,omitempty"`
 	WorkingDir string            `json:"working_dir,omitempty"`
+	Disabled   bool              `json:"disabled,omitempty"`
 
 	// Process-only.
 	Shell bool `json:"shell,omitempty"`
 
 	// Agent-only. SPEC §10.
-	MCPInjection     *MCPInjection  `json:"mcp_injection,omitempty"`
-	ReadySignal      *ReadySignal   `json:"ready_signal,omitempty"`
-	ChromeTrimHints  []string       `json:"chrome_trim_hints,omitempty"`
-	IdleDetection    *IdleDetection `json:"idle_detection,omitempty"`
+	MCPInjection    *MCPInjection  `json:"mcp_injection,omitempty"`
+	ReadySignal     *ReadySignal   `json:"ready_signal,omitempty"`
+	ChromeTrimHints []string       `json:"chrome_trim_hints,omitempty"`
+	IdleDetection   *IdleDetection `json:"idle_detection,omitempty"`
 }
 
 // IdleDetection configures steady-state idle classification for an
@@ -119,28 +121,22 @@ type Set struct {
 	Processes []*Preset
 }
 
-// Load scans the standard locations under $XDG_CONFIG_HOME/patterm/
-// presets/{agents,processes}/*.json. Unknown files are skipped with a
-// warning to stderr; the spec is forgiving here.
+// Load returns the built-in presets plus user overlays from
+// $XDG_CONFIG_HOME/patterm/presets/{agents,processes}/*.json. Startup
+// does not write default files; user files only override or extend the
+// in-memory defaults. A user overlay with {"disabled": true} hides a
+// built-in preset of the same name.
 func Load() (Set, error) {
 	base, err := ConfigDir()
 	if err != nil {
 		return Set{}, err
 	}
-	if err := os.MkdirAll(base, 0o700); err != nil {
-		return Set{}, fmt.Errorf("preset: mkdir %s: %w", base, err)
-	}
 
-	// Make sure the default-preset files exist on first run. Idempotent.
-	if err := ensureDefaults(base); err != nil {
-		return Set{}, err
-	}
-
-	agents, err := loadDir(filepath.Join(base, "presets", "agents"), KindAgent)
+	agents, err := loadWithDefaults(filepath.Join(base, "presets", "agents"), KindAgent, defaultAgentPresets())
 	if err != nil {
 		return Set{}, err
 	}
-	procs, err := loadDir(filepath.Join(base, "presets", "processes"), KindCommand)
+	procs, err := loadWithDefaults(filepath.Join(base, "presets", "processes"), KindCommand, nil)
 	if err != nil {
 		return Set{}, err
 	}
@@ -160,51 +156,154 @@ func ConfigDir() (string, error) {
 	return filepath.Join(home, ".config", "patterm"), nil
 }
 
-func loadDir(dir string, kind Kind) ([]*Preset, error) {
-	if err := os.MkdirAll(dir, 0o700); err != nil {
-		return nil, fmt.Errorf("preset: mkdir %s: %w", dir, err)
+func loadWithDefaults(dir string, kind Kind, defaults []*Preset) ([]*Preset, error) {
+	byName := make(map[string]*Preset, len(defaults))
+	for _, p := range defaults {
+		cp := clonePreset(p)
+		cp.Kind = kind
+		byName[cp.Name] = cp
 	}
+
 	entries, err := os.ReadDir(dir)
 	if err != nil {
+		if os.IsNotExist(err) {
+			return sortedPresets(byName), nil
+		}
 		return nil, fmt.Errorf("preset: read %s: %w", dir, err)
 	}
-	var out []*Preset
 	for _, e := range entries {
 		if e.IsDir() || !strings.HasSuffix(e.Name(), ".json") {
 			continue
 		}
 		path := filepath.Join(dir, e.Name())
-		p, err := loadFile(path, kind)
+		p, err := loadFileOverlay(path, kind, byName)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "patterm: preset %s: %v\n", path, err)
 			continue
 		}
+		if p.Disabled {
+			delete(byName, p.Name)
+			continue
+		}
+		byName[p.Name] = p
+	}
+	return sortedPresets(byName), nil
+}
+
+func sortedPresets(byName map[string]*Preset) []*Preset {
+	out := make([]*Preset, 0, len(byName))
+	for _, p := range byName {
 		out = append(out, p)
 	}
 	sort.Slice(out, func(i, j int) bool { return out[i].Name < out[j].Name })
-	return out, nil
+	return out
 }
 
-func loadFile(path string, kind Kind) (*Preset, error) {
+func loadFileOverlay(path string, kind Kind, defaults map[string]*Preset) (*Preset, error) {
 	b, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}
+	var header struct {
+		Name     string `json:"name"`
+		Disabled bool   `json:"disabled,omitempty"`
+	}
+	if err := json.Unmarshal(b, &header); err != nil {
+		return nil, err
+	}
+	if header.Name == "" {
+		return nil, errors.New("missing 'name'")
+	}
+	if def := defaults[header.Name]; def != nil {
+		p, err := mergePreset(def, b)
+		if err != nil {
+			return nil, err
+		}
+		p.Path = path
+		p.Kind = kind
+		return p, validatePreset(p)
+	}
+	var p Preset
+	if err := json.Unmarshal(b, &p); err != nil {
+		return nil, err
+	}
+	p.Path = path
+	p.Kind = kind
+	return &p, validatePreset(&p)
+}
+
+func validatePreset(p *Preset) error {
+	if p.Name == "" {
+		return errors.New("missing 'name'")
+	}
+	if p.Disabled {
+		return nil
+	}
+	if len(p.Argv) == 0 && !p.Shell {
+		return errors.New("missing 'argv'")
+	}
+	return nil
+}
+
+func mergePreset(def *Preset, overlay []byte) (*Preset, error) {
+	base, err := presetMap(def)
+	if err != nil {
+		return nil, err
+	}
+	var over map[string]any
+	dec := json.NewDecoder(bytes.NewReader(overlay))
+	dec.UseNumber()
+	if err := dec.Decode(&over); err != nil {
+		return nil, err
+	}
+	deepMerge(base, over)
+	b, err := json.Marshal(base)
+	if err != nil {
+		return nil, err
+	}
 	var p Preset
 	if err := json.Unmarshal(b, &p); err != nil {
 		return nil, err
 	}
-	if p.Name == "" {
-		return nil, errors.New("missing 'name'")
-	}
-	if len(p.Argv) == 0 && !p.Shell {
-		return nil, errors.New("missing 'argv'")
-	}
-	p.Path = path
-	p.Kind = kind
 	return &p, nil
 }
 
+func presetMap(p *Preset) (map[string]any, error) {
+	b, err := json.Marshal(p)
+	if err != nil {
+		return nil, err
+	}
+	var m map[string]any
+	dec := json.NewDecoder(bytes.NewReader(b))
+	dec.UseNumber()
+	if err := dec.Decode(&m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func deepMerge(dst, src map[string]any) {
+	for k, v := range src {
+		if sm, ok := v.(map[string]any); ok {
+			if dm, ok := dst[k].(map[string]any); ok {
+				deepMerge(dm, sm)
+				continue
+			}
+		}
+		dst[k] = v
+	}
+}
+
+func clonePreset(p *Preset) *Preset {
+	if p == nil {
+		return nil
+	}
+	b, _ := json.Marshal(p)
+	var out Preset
+	_ = json.Unmarshal(b, &out)
+	return &out
+}
+
 // ResolvedArgv returns the argv to actually exec, handling the
 // process-preset "shell: true" case (SPEC §10).
 func (p *Preset) ResolvedArgv() []string {
@@ -214,17 +313,9 @@ func (p *Preset) ResolvedArgv() []string {
 	return p.Argv
 }
 
-// ensureDefaults writes default agent presets (claude/codex/opencode)
-// and a sample process preset on first run. Never overwrites existing
-// user files.
-func ensureDefaults(base string) error {
-	defaults := []struct {
-		rel  string
-		body string
-	}{
-		{
-			"presets/agents/claude.json",
-			`{
+func defaultAgentPresets() []*Preset {
+	bodies := []string{
+		`{
   "name": "claude",
   "argv": ["claude"],
   "mcp_injection": { "kind": "flag", "flag": "--mcp-config" },
@@ -249,10 +340,7 @@ func ensureDefaults(base string) error {
   ]
 }
 `,
-		},
-		{
-			"presets/agents/codex.json",
-			`{
+		`{
   "name": "codex",
   "argv": ["codex"],
   "mcp_injection": {
@@ -264,7 +352,10 @@ func ensureDefaults(base string) error {
   "ready_signal": { "idle_ms": 1000 },
   "idle_detection": {
     "strategy": "osc_title_stability",
-    "idle_threshold_ms": 2000
+    "idle_threshold_ms": 2000,
+    "thinking_patterns": [
+      "(?i)esc to interrupt"
+    ]
   },
   "chrome_trim_hints": [
     "^OpenAI Codex",
@@ -275,10 +366,7 @@ func ensureDefaults(base string) error {
   ]
 }
 `,
-		},
-		{
-			"presets/agents/opencode.json",
-			`{
+		`{
   "name": "opencode",
   "argv": ["opencode"],
   "mcp_injection": {
@@ -301,19 +389,15 @@ func ensureDefaults(base string) error {
   ]
 }
 `,
-		},
 	}
-	for _, d := range defaults {
-		full := filepath.Join(base, d.rel)
-		if _, err := os.Stat(full); err == nil {
-			continue
-		}
-		if err := os.MkdirAll(filepath.Dir(full), 0o700); err != nil {
-			return err
-		}
-		if err := os.WriteFile(full, []byte(d.body), 0o600); err != nil {
-			return err
+	out := make([]*Preset, 0, len(bodies))
+	for _, body := range bodies {
+		var p Preset
+		if err := json.Unmarshal([]byte(body), &p); err != nil {
+			panic(err)
 		}
+		p.Kind = KindAgent
+		out = append(out, &p)
 	}
-	return nil
+	return out
 }

internal/preset/preset_test.go

@@ -0,0 +1,131 @@
+package preset
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoadUsesBuiltInDefaultsWithoutWritingConfig(t *testing.T) {
+	configHome := filepath.Join(t.TempDir(), "config")
+	t.Setenv("XDG_CONFIG_HOME", configHome)
+
+	set, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(configHome, "patterm")); !os.IsNotExist(err) {
+		t.Fatalf("Load created config dir or unexpected stat error: %v", err)
+	}
+	if len(set.Agents) != 3 {
+		t.Fatalf("agents len = %d, want 3", len(set.Agents))
+	}
+	claude := presetByName(set.Agents, "claude")
+	if claude == nil {
+		t.Fatal("missing built-in claude preset")
+	}
+	if claude.IdleDetection == nil || len(claude.IdleDetection.PermissionPatterns) == 0 {
+		t.Fatalf("built-in claude missing permission patterns: %+v", claude.IdleDetection)
+	}
+	codex := presetByName(set.Agents, "codex")
+	if codex == nil {
+		t.Fatal("missing built-in codex preset")
+	}
+	if codex.IdleDetection == nil || len(codex.IdleDetection.ThinkingPatterns) == 0 {
+		t.Fatalf("built-in codex missing thinking patterns: %+v", codex.IdleDetection)
+	}
+}
+
+func TestLoadMergesUserOverlayIntoBuiltInPreset(t *testing.T) {
+	configHome := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", configHome)
+	dir := filepath.Join(configHome, "patterm", "presets", "agents")
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		t.Fatal(err)
+	}
+	writeFile(t, filepath.Join(dir, "claude.json"), `{
+  "name": "claude",
+  "argv": ["claude", "--model", "sonnet"],
+  "idle_detection": { "idle_threshold_ms": 3500 }
+}`)
+
+	set, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	claude := presetByName(set.Agents, "claude")
+	if claude == nil {
+		t.Fatal("missing claude preset")
+	}
+	if got := claude.Argv; len(got) != 3 || got[0] != "claude" || got[2] != "sonnet" {
+		t.Fatalf("argv = %#v", got)
+	}
+	if claude.IdleDetection.IdleThresholdMS != 3500 {
+		t.Fatalf("idle threshold = %d", claude.IdleDetection.IdleThresholdMS)
+	}
+	if len(claude.IdleDetection.PermissionPatterns) == 0 {
+		t.Fatalf("permission patterns were not inherited: %+v", claude.IdleDetection)
+	}
+	if claude.MCPInjection == nil || claude.MCPInjection.Kind != "flag" {
+		t.Fatalf("mcp injection was not inherited: %+v", claude.MCPInjection)
+	}
+}
+
+func TestLoadCanDisableBuiltInPreset(t *testing.T) {
+	configHome := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", configHome)
+	dir := filepath.Join(configHome, "patterm", "presets", "agents")
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		t.Fatal(err)
+	}
+	writeFile(t, filepath.Join(dir, "opencode.json"), `{"name":"opencode","disabled":true}`)
+
+	set, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if presetByName(set.Agents, "opencode") != nil {
+		t.Fatal("opencode preset was not disabled")
+	}
+	if presetByName(set.Agents, "claude") == nil || presetByName(set.Agents, "codex") == nil {
+		t.Fatalf("other built-ins missing: %+v", set.Agents)
+	}
+}
+
+func TestLoadAddsCustomUserPreset(t *testing.T) {
+	configHome := t.TempDir()
+	t.Setenv("XDG_CONFIG_HOME", configHome)
+	dir := filepath.Join(configHome, "patterm", "presets", "processes")
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		t.Fatal(err)
+	}
+	writeFile(t, filepath.Join(dir, "test.json"), `{"name":"test","argv":["go","test","./..."]}`)
+
+	set, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	proc := presetByName(set.Processes, "test")
+	if proc == nil {
+		t.Fatal("missing custom process preset")
+	}
+	if proc.Kind != KindCommand {
+		t.Fatalf("kind = %q", proc.Kind)
+	}
+}
+
+func presetByName(ps []*Preset, name string) *Preset {
+	for _, p := range ps {
+		if p.Name == name {
+			return p
+		}
+	}
+	return nil
+}
+
+func writeFile(t *testing.T, path, body string) {
+	t.Helper()
+	if err := os.WriteFile(path, []byte(body), 0o600); err != nil {
+		t.Fatal(err)
+	}
+}