## Summary
Prevents the FN-8471 failure mode where planner overseer `retry_step`
bounced `in-progress → todo` while a live step-execute session was still
coding, hard-cancelling the agent up to three times until recovery
budget exhausted.
Also closes concurrent resume races after plan-review release that
parked `status=failed` on a losing graph while a peer session still
owned work.
### Changes
- **Overseer live gate:** `retryStep` skips the hard-cancel bounce when
`isTaskLiveForOverseerRetry` is true; returns `false` so attempt budget
is not burned; durable skip log is deduped per task/stage.
- **Single-flight graph dispatch:** `executeCore` claims `graphRouting`
before any await; `executeWorkflowGraph({ alreadyClaimed })` owns
release.
- **Single-flight unpause resume:** claim `resumingUnpaused` before
await; treat existing graph claim as already-owned; clear claim before
completed-work recovery.
- **No false park:** execute-family graph endings with a peer live
session no longer stamp `status=failed` (merge-region failures still
park).
### Tests
- `executor-live-overseer-retry-gate.test.ts` — live probe matrix,
execute-family preserve, merge still parks
- `planner-overseer-intervention-wiring.test.ts` — live skip keeps
column in-progress and `getAttemptCount === 0`
## Test plan
- [x] `vitest run` scoped to the two new/updated test files (16 passed)
- [ ] CI gate (lint/typecheck/build/test:gate)
- [ ] Optional manual: fail a raced graph with a live step session and
confirm overseer does not bounce to todo
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Bug Fixes**
- Improved overseer-retry “live session” gating to avoid interrupting
active work, covering more live surfaces and preventing multi-resume
races.
- Updated failure handling so execute-family failures can be preserved
when another live session is still running, while merge-attempt failures
are still marked failed.
- Added deduping for “retry skipped due to live session” logs so they’re
emitted only once per task stage, and ensured the recovery attempt
budget isn’t consumed when intentionally skipped.
- **Tests**
- Added coverage for live-gating, retry-skip/budget behavior, and the
revised failure-parking rules.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
6422cb93a4