Add tests and implement timeline ingestion options with NATS and Redis subscribers

- Introduced `BinaryReachabilityLifterTests` to validate binary lifting functionality.
- Created `PackRunWorkerOptions` for configuring worker paths and execution persistence.
- Added `TimelineIngestionOptions` for configuring NATS and Redis ingestion transports.
- Implemented `NatsTimelineEventSubscriber` for subscribing to NATS events.
- Developed `RedisTimelineEventSubscriber` for reading from Redis Streams.
- Added `TimelineEnvelopeParser` to normalize incoming event envelopes.
- Created unit tests for `TimelineEnvelopeParser` to ensure correct field mapping.
- Implemented `TimelineAuthorizationAuditSink` for logging authorization outcomes.

docs/db/CONVERSION_PLAN.md

@@ -231,7 +231,7 @@ See:
 2. Implement schema migrations
 3. Implement repository interfaces
 4. Add configuration switch
-5. Enable dual-write (if Tier A)
+5. (Retired) Dual-write was used during migration for Tier A; all modules are now Postgres-only.
 6. Run verification tests
 7. Switch to PostgreSQL-only
 8. Archive MongoDB data
@@ -293,7 +293,7 @@ Each phase has independent rollback capability:
 | Level | Action | Recovery Time |
 |-------|--------|---------------|
 | Configuration | Change `Persistence:<Module>` to `Mongo` | Minutes |
-| Data | MongoDB data retained during dual-write | None needed |
+| Data | MongoDB data retained during dual-write | None needed (historical note; dual-write ended after cutover) |
 | Code | Git revert (PostgreSQL code isolated) | Hours |
 
 ---