Retry malformed agent file notes within the same run

[itsjling]

What to build

When a coding agent returns malformed notes for some files, retry only those failed file notes during the same run. Keep every valid file note and any valid change note already produced. Bound the retries so a provider that keeps returning bad output cannot create an endless loop. If all attempts fail, keep the current per-file failure details and later-retry behavior.

Acceptance criteria

• A file note that omits a required field, such as details, gets another attempt during the same run.
• A retry requests only notes that failed validation; valid notes from the first attempt remain intact.
• Retries have a clear fixed limit and cannot loop without end.
• A successful retry marks the note run complete and publishes the recovered notes.
• Exhausted retries preserve the per-file failure reasons and the existing retry-after-diff-change-or-restart behavior.
• Tests cover a missing details field, partial batch success, successful recovery, and retry exhaustion.

Blocked by

• None — can start immediately.