MC-4499

Coder gate for MC-4494 / Control Room v2 first behavior-changing slice. Objective: Behind a default-off feature flag, make WAT/workflow dispatch actions notify the Controller instead of auto-dispatching/reassigning/spawning runtimes. Feature flag: - Suggested name: MC_CONTROL_ROOM_V2_CONTROLLER_NOTIFY - Default off; existing behavior must remain when unset/false. Target anchors from preflight: - app.py `_INLINE_DISPATCH_INSTRUCTIONS` - app.py `_INLINE_DISPATCH_ROLES` - app.py `_dispatch_workflow_action_inline()` - app.py `api_workflow_action()` - tests around workflow action/idempotency/runtime dispatch. Required behavior under flag: - Dispatch actions such as `send_to_larry`, `send_to_tessa`, `send_to_council`, `return_for_fixes` create a durable Controller notification/audit comment. - Return API success with a clear marker such as `queued_for_controller: true` / `controller_notify: true`. - Do NOT call `_dispatch_workflow_action_inline()`. - Do NOT call `_queue_and_pickup()`. - Do NOT inject into tmux/runtime. - Do NOT change `assigned_to` or force `status='todo'`. - State-only actions like approve/close remain current behavior for this slice. Required tests: - Flag off preserves current workflow-action dispatch behavior or existing tests remain green. - Flag on dispatch action writes Controller/audit comment and returns controller notification marker. - Flag on dispatch action does not reassign, does not status-flip, and does not create runtime/queued pickup side effects. - Tests should be focused and deterministic; monkeypatch runtime/pickup helpers where needed. Constraints: - Runtime/model guidance remains advisory; Controller can choose any fitting capability. - Do not change comment route or Telegram behavior yet; those are later slices. - Do not collapse board statuses yet. - Use dev-loop/project hooks as required; do not bypass. Expected check-in: 2026-05-31 17:57:49 UTC.