## Summary
Make `taskIdentifier` optional on the run-queue message schema. No
behavior change in this PR; readers continue to accept payloads that
include the field. A separate change will stop writing it on the wire to
shrink the per-run payload that lives in Redis while runs wait to be
dequeued.
## Design
The field is written into every payload at enqueue time but no consumer
reads it back on the dequeue path. Both the run-engine and supervisor
derive `taskIdentifier` from the loaded `TaskRun` row instead. Relaxing
the schema first means readers tolerate payloads that omit it, so the
writer-side change can ship without producing schema-parse errors during
a rolling deploy.
`projectId` is left required: `WorkerQueueResolver.#getOverride` reads
it for project-scoped runtime worker-queue overrides.
## Test plan
- [x] `pnpm run typecheck --filter @internal/run-engine`
- [x] `pnpm run typecheck --filter webapp`
- [x] `pnpm run test ./src/run-queue/tests/enqueueMessage.test.ts
./src/run-queue/tests/workerQueueResolver.test.ts --run` (28/28 passing)
Eric Allam
2301ed608c