## Summary
Follow-up after **#2164** and main’s **FN-8103 / FN-8104**
(Postgres-only data access / SQLite retirement).
Main already routes Quality through `AsyncQualityStore` +
`getAsyncLayer()`. This PR keeps the **review hardening** that was still
missing:
- **Project binding** — reject request `projectId` mismatches vs bound
AsyncDataLayer; all SQL uses bound project
- **`createRunIfNoActive`** — advisory lock so concurrent starts cannot
double-queue
- **Cancel-safe runner** — cancel slot registered before the running
write; pre-spawn cancel skips process
- **`finalizeRun`** — never overwrites a `cancelled` terminal status
- **Detached execute** — catch only execution failures; prune fail-soft
in `finally`
- Guardrail tests + Quality v2 plan doc
## Test plan
- [ ] Task QA loads under PostgreSQL (no SQLite/backend-mode error)
- [ ] Concurrent start for same task → 409 second start
- [ ] Cancel during start does not leave a live orphan process
- [ ] Cancelled run stays cancelled after process exit
- [ ] `pnpm --filter @fusion-plugin-examples/quality test` (37 tests)
446c969968