Removes the retained-worktree store end to end: the daemon's state-dir
store, GET/DELETE /api/worktrees, `maestro worktrees list|reclaim`, the
TUI overlay behind `w`, and the web `#/worktrees` view and header link.
The kill guard stays. A forced kill and a dirty natural exit now leave
the worktree on disk untouched instead of parking it in a store, so
removing one is an ordinary `git worktree remove`. A pristine tree is
still removed on exit. DELETE /api/sessions/:id always answers 204.
The header's debug button also goes; Ctrl+Shift+D and `?hud` still
toggle the HUD.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
--force overrides the kill refusal and nothing else (#81). The guarded
worktree is recorded in the retained store with reason force-killed —
never removed — and the outcome names what was kept so a client can say
where the work went. A tree whose guard is clear never needed the
override; force removes it as usual.
The store write happens before teardown, so a failed retention leaves
the session running and every artifact intact. DELETE /api/sessions/:id
takes ?force=true and answers 200 with KillOutcome; the unforced kill
keeps its 204.
Collapses the two probes #79 and #80 grew in parallel into one:
worktree_probe::in_the_way is the single predicate behind the kill
refusal, the retained list, and the natural-exit classifier to come.
Keeps #79's in-worktree resolution (detached HEAD, missing directory)
and #80's InTheWay payload, and drops the duplicate UnsavedWork type.
Closes#79
