Triage announced specification completion before its finally block marked the
plan work item terminal, so the Plan Review seeder saw its own still-running
predecessor as an "active continuation", bailed, and the discarded result
silently stranded the card until FN-8592 self-healing re-seeded it ~10 minutes
later (529 occurrences in 18 days).
- seedStrandedPlanReviewContinuation gains retirePredecessorId: idle check
excludes the named predecessor, then retires it and installs the successor in
ONE transaction under the task lock; a bailed seed mutates nothing.
- triage threads planningWorkItemId through PlanningHandoffReport; the runtime
reaction passes it as retirePredecessorId.
- reactToSpecificationComplete consumes the seed result: typed quiet parks
(incl. new "no-pre-release-plan-review"), bounded retries with a fresh
task/IR snapshot per attempt (mid-retry pause/needs-replan honored), loud
warning naming self-healing on exhaustion.
- Tests: PG both-orderings/no-mutation-on-bail/cross-task cases, direct engine
seeder handoff cases, reaction retry/park/pause/replan cases.
- docs/solutions: new planning-handoff-race writeup; graph-entry-contract doc
reclassifies the FN-8592 sweep as backstop-only.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>