feat(#176): Integrate M4.2 infrastructure with M4.1 coordinator

Add CoordinatorIntegrationModule providing REST API endpoints for the Python
coordinator to communicate with the NestJS API infrastructure:

- POST /coordinator/jobs - Create job from coordinator webhook events
- PATCH /coordinator/jobs/:id/status - Update job status (PENDING -> RUNNING)
- PATCH /coordinator/jobs/:id/progress - Update job progress percentage
- POST /coordinator/jobs/:id/complete - Mark job complete with results
- POST /coordinator/jobs/:id/fail - Mark job failed with gate results
- GET /coordinator/jobs/:id - Get job details with events and steps
- GET /coordinator/health - Integration health check

Integration features:
- Job creation dispatches to BullMQ queues
- Status updates emit JobEvents for audit logging
- Completion/failure events broadcast via Herald to Discord
- Status transition validation (PENDING -> QUEUED -> RUNNING -> COMPLETED/FAILED)
- Health check includes BullMQ connection status and queue counts

Also adds JOB_PROGRESS event type to event-types.ts for progress tracking.

Fixes #176

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/scratchpads/176-coordinator-integration.md

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+# Issue #176: Coordinator Integration
+
+## Objective
+
+Integrate M4.2 infrastructure (NestJS API) with M4.1 coordinator (Python FastAPI) to enable seamless job orchestration between the two systems.
+
+## Architecture Analysis
+
+### M4.1 Coordinator (Python)
+
+- FastAPI application at `apps/coordinator`
+- Handles Gitea webhooks, queue management, agent orchestration
+- Uses file-based JSON queue for persistence
+- Has QueueManager, Coordinator, and OrchestrationLoop classes
+- Exposes `/webhook/gitea` and `/health` endpoints
+
+### M4.2 Infrastructure (NestJS)
+
+- StitcherModule: Workflow orchestration, webhook handling, job dispatch
+- RunnerJobsModule: CRUD for RunnerJob entities, BullMQ integration
+- JobEventsModule: Event tracking and audit logging
+- JobStepsModule: Step tracking for jobs
+- HeraldModule: Status broadcasting to Discord
+- BullMqModule: Queue infrastructure with Valkey backend
+- BridgeModule: Discord integration
+
+## Integration Design
+
+### Flow 1: Webhook -> Job Creation
+
+```
+Gitea -> Coordinator (Python) -> NestJS API -> RunnerJob + BullMQ
+                              ^
+                              | HTTP POST /api/coordinator/jobs
+```
+
+### Flow 2: Job Status Updates
+
+```
+Coordinator (Python) -> NestJS API -> JobEvent -> Herald -> Discord
+                      ^
+                      | HTTP PATCH /api/coordinator/jobs/:id/status
+```
+
+### Flow 3: Job Completion
+
+```
+Coordinator (Python) -> NestJS API -> Complete RunnerJob -> Herald broadcast
+                      ^
+                      | HTTP POST /api/coordinator/jobs/:id/complete
+```
+
+## Implementation Plan
+
+### 1. Create Coordinator Integration Module
+
+- `apps/api/src/coordinator-integration/`
+  - `coordinator-integration.module.ts` - NestJS module
+  - `coordinator-integration.controller.ts` - REST endpoints for Python coordinator
+  - `coordinator-integration.service.ts` - Business logic
+  - `dto/` - DTOs for coordinator communication
+  - `interfaces/` - Type definitions
+
+### 2. Endpoints for Python Coordinator
+
+- `POST /api/coordinator/jobs` - Create job from coordinator
+- `PATCH /api/coordinator/jobs/:id/status` - Update job status
+- `POST /api/coordinator/jobs/:id/complete` - Mark job complete
+- `POST /api/coordinator/jobs/:id/fail` - Mark job failed
+- `GET /api/coordinator/health` - Integration health check
+
+### 3. Event Bridging
+
+- When coordinator reports progress -> emit JobEvent
+- When coordinator completes -> update RunnerJob + emit completion event
+- Herald subscribes and broadcasts to Discord
+
+## TDD Approach
+
+1. Write tests for CoordinatorIntegrationService
+2. Write tests for CoordinatorIntegrationController
+3. Implement minimal code to pass tests
+4. Refactor
+
+## Progress
+
+- [x] Analyze coordinator structure
+- [x] Analyze M4.2 infrastructure
+- [x] Design integration layer
+- [x] Write failing tests for service
+- [x] Implement service
+- [x] Write failing tests for controller
+- [x] Implement controller
+- [x] Add DTOs and interfaces
+- [x] Run quality gates
+- [x] Commit
+
+## Notes
+
+- The Python coordinator uses httpx.AsyncClient for HTTP calls
+- API auth can be handled via shared secret (API key)
+- Events follow established patterns from job-events module