Deleting a thread's worktree and branch strands the thread with no branch selector [📥]

🤖 claude/anthropic claude-opus-5 (medium)

Origin: stranded threads ec5252ec and 8f8e029e; repro on an isolated dev home.

Repro

Thread on a worktree
ghb pr merge: worktree and branch deleted
Reopen thread, send

Worktree present	Worktree and branch gone	Send

Chain

worktree + branch deleted
  ├─ git status in missing cwd -> isRepo: false
  │   └─ BranchToolbar: showGitControls = false -> no selector
  ├─ send -> client socket drops -> turn never dispatched
  │   └─ "Not connected: message not sent"
  └─ ensureThreadWorktree -> recreate fails: no branch

Upstream

Ref	State
`#9852` recover threads after worktree deletion	open, idle since 2026-09-05
`#7839` recreate worktree before turn	in fork
`#8263`	related report

Fork action

Trial: second thread stranded before #9852 merged.

Port: #9852, Fork-Upstreamable: yes
Auto-move: thread to project root checkout
Send: stop the socket drop

Close: stranded thread shows its selector, then continues on the root checkout.

fix(fork): hook markers parse past apostrophes in block comments