A failed auto-commit still advances the workflow from the old HEAD

TODO.md

@@ -2,8 +2,6 @@
 
 - Merge finalization keeps no durable progress; cleanup runs before the task is closed
   `internal/agents/mergein.go:303–324` runs push → notes → fast-forward → `RemoveTask` → `MergeTask`. A crash or error after the push leaves an active task with no worktree; a retried Merge fails in `Snapshot`, or squashes to no change and closes with an empty `merge_commit`. Have the `finalizing` marker record the squash commit; on startup, a recorded commit that is an ancestor of origin/<default> finishes notes, fast-forward, removal and MergeTask idempotently, otherwise the marker is cleared and an error is filed.
-- A failed auto-commit still advances the workflow from the old HEAD
-  A `CommitAll` error is only logged (`internal/agents/manager.go:838–841`) and `FinishStage` still runs (`:885–889`), so `RecordStage` stores the old `git.Head` (`internal/agents/workflows.go:349–356`), the next stage branches without the turn's work, and `discardStages` later deletes the worktree that held it. On commit failure, treat the turn as unfinished: skip FinishStage, the handoff and the summary, and file the error in the task's inbox.
 - Codex mid-turn delivery deletes input before the steer is accepted
   Queued inputs are deleted or marked delivered and recorded as `user.message` (`internal/agents/queue.go:119`, `:158`; `internal/agents/inbox.go:404`) before `Steer`, whose error is only logged (`internal/agents/codex.go:167–174`). Return the consumed ids from `deliverMidTurn`; when Steer fails, re-insert the inputs in order and clear `delivered_at` so the turn-end Deliver sends them.
 - Inbox answer validation isn't atomic with resolving the question