Rename Kill to Close, add New Terminal palette entry, clean up exited terminals

- Palette's per-child "Kill <name>" action is now labelled "Close <name>"
  (action kind unchanged; still SIGTERM). Matches the existing "Close
  agent: …" context entry and reads less violent for a graceful term.
- New "New Terminal" palette entry spawns a bare interactive $SHELL pane
  via LaunchTerminal (kind=terminal). Replaces the default "shell"
  process preset that was seeded on first run.
- Exited KindTerminal entries are now dropped from the session in
  reapChild — terminals have no restart path, so leaving them behind as
  greyed rows in the Processes sidebar was just clutter. processList
  also filters defensively.

CHANGELOG.md

@@ -7,6 +7,13 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ## [Unreleased]
 
 ### Added
+- "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`,
+  terminals are ephemeral — once they exit they vanish from the
+  Processes sidebar instead of lingering as a dead row. The default
+  `shell` process preset that previously seeded on first run has been
+  removed; this entry replaces it.
 - Per-child idle-state classifier with five states (`idle`, `working`,
   `thinking`, `permission`, `error`) and three pluggable strategies:
   `output_activity` (claude / opencode defaults), `osc_title_stability`
@@ -98,6 +105,11 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   after a child program disables mouse tracking.
 
 ### Changed
+- The palette's per-child "Kill <name>" action is now labelled
+  "Close <name>". The underlying signal (SIGTERM) and behaviour are
+  unchanged; the new label matches the existing "Close agent: …"
+  context entry and reads less violent for what is really just a
+  graceful termination.
 - `timer_wait` is now a thin wrapper over the shared timer manager
   (`timer_set` semantics). Existing callers see no behavioural change;
   the timer is visible in `timer_list` while it's pending.
@@ -108,6 +120,12 @@ loosely follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   renders the canonical `--flag` form.
 
 ### Fixed
+- 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
+  sidebar as soon as they exit. Previously they stuck around as a
+  greyed-out row indistinguishable from an exited command process,
+  even though terminals have no restart path.
 - `whoami` and `help("timers")` now advertise the full Solo-parity timer
   surface (`timer_set`, `timer_fire_when_idle_any`,
   `timer_fire_when_idle_all`, `timer_cancel`, `timer_pause`,