Simplify session lifecycle and MCP cleanup

CHANGELOG.md

@@ -34,6 +34,16 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   available macros.
 
 ### Changed
+- Focus, lifecycle, and repaint paths now capture terminal layout before
+  taking UI state locks, reducing resize-time deadlock risk without
+  changing visible behavior.
+- Focused PTY output no longer rebuilds the scratchpad sidebar on every
+  chunk. The sidebar still repaints on focus/lifecycle/resize changes
+  and when child output scrolls over the chrome, but normal output avoids
+  repeated scratchpad disk reads.
+- Harness scenario tests now reuse one built patterm binary per test run
+  and write failure artifacts under a repo-rooted, collision-proof
+  directory.
 - Palette ordering: open agents/processes (`Switch to …`) now appear
   above the option to spawn new ones, with kill entries pushed down
   toward the end of the list.
@@ -45,6 +55,21 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   extra row of viewport.
 
 ### Fixed
+- Agent MCP injection no longer writes unused config files for inline
+  injection modes (`cli_override` / `config_env`). File-backed injection
+  modes track their generated paths and clean them up when the child is
+  closed, exits, or patterm shuts down.
+- MCP `tools/list` descriptions now match the runtime argument values
+  for process output and pattern waiting, and typed invalid-argument
+  errors map to JSON-RPC invalid params instead of generic internal
+  errors.
+- Scratchpad writes and appends are serialized inside a patterm process
+  so `expected_revision` checks cannot race another local scratchpad
+  mutation.
+- The sidebar scratchpad list now refreshes after MCP
+  `scratchpad_write` and `scratchpad_append` calls.
+- UI chrome now reads renamed child display names through the
+  `DisplayName` accessor, avoiding races with `rename_process`.
 - Child processes spawned by an orchestrator are now killed when the
   orchestrator dies, recursively through the tree. Applies whether the
   parent was closed via MCP, Ctrl-C'd by the user, or exited on its