- Port thread pinning (#5312) into the orchestration-v2 command pipeline:
  thread.pin/unpin commands, thread.pinned/unpinned events, pinnedAt on the
  v2 thread state and projected shells, promotion semantics (pin clears
  settle/snooze, settle clears pin) matching the v1 decider, and client
  pin/unpin operations in the v2 dispatch style.
- Port the regenerated-title context anchoring (#5365) into
  ThreadTitleRegenerationService: pin the first user message ahead of the
  retained tail when the digest is truncated.
- Re-apply the right-panel controls positioning from #5260 to the v2
  ChatView title bar controls.
- Repair merge artifacts: committed conflict markers in BranchToolbar,
  duplicate capability keys, duplicate CommandPalette import, v1 turn
  naming in DiffPanel's focus-refresh effect, onSend signature merge.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>