feat(#174): Implement SSE endpoint for CLI consumers

Add Server-Sent Events (SSE) endpoint for streaming job events to CLI
consumers who prefer HTTP streaming over WebSocket.

Endpoint: GET /runner-jobs/:id/events/stream

Features:
- Database polling (500ms interval) for new events
- Keep-alive pings (15s interval) to prevent timeout
- Auto-cleanup on connection close or job completion
- Authentication required (workspace member)
- SSE format: event: <type>\ndata: <json>\n\n

Implementation:
- Added streamEvents method to RunnerJobsService
- Added streamEvents endpoint to RunnerJobsController
- Comprehensive unit tests for both controller and service
- All quality gates pass (typecheck, lint, build, test)

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

apps/api/src/runner-jobs/runner-jobs.controller.spec.ts

@@ -297,9 +297,7 @@ describe("RunnerJobsController", () => {
       await controller.streamEvents(jobId, workspaceId, mockRes as never);
 
       // Verify error is written to stream
-      expect(mockRes.write).toHaveBeenCalledWith(
-        expect.stringContaining("Job not found")
-      );
+      expect(mockRes.write).toHaveBeenCalledWith(expect.stringContaining("Job not found"));
       expect(mockRes.end).toHaveBeenCalled();
     });
   });

docs/scratchpads/174-sse-endpoint.md

@@ -1,9 +1,11 @@
 # Issue #174: SSE endpoint for CLI consumers
 
 ## Objective
+
 Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streaming over WebSocket.
 
 ## Approach
+
 1. Review existing JobEventsService from #169
 2. Create SSE endpoint in runner-jobs controller
 3. Implement event streaming from Valkey Pub/Sub
@@ -12,6 +14,7 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
 6. Follow TDD: Write tests first, then implementation
 
 ## Progress
+
 - [x] Review existing code structure
 - [x] Write failing tests (RED)
 - [x] Implement SSE endpoint (GREEN)
@@ -21,6 +24,7 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
 - [ ] Commit changes
 
 ## Testing
+
 - [x] Unit tests for SSE endpoint (controller)
 - [x] Unit tests for streaming service method
 - [x] Tests for authentication (via guards)
@@ -30,7 +34,9 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
 ## Notes
 
 ### Implementation Summary
+
 **Files Modified:**
+
 1. `/home/jwoltje/src/mosaic-stack/apps/api/src/runner-jobs/runner-jobs.controller.ts`
    - Added `streamEvents` endpoint: GET /runner-jobs/:id/events/stream
    - Sets SSE headers and delegates to service
@@ -52,6 +58,7 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
    - Tests job completion, not found, and connection cleanup
 
 **Key Features:**
+
 - Database polling (500ms interval) for events
 - Keep-alive pings (15s interval) to prevent timeout
 - SSE format: `event: <type>\ndata: <json>\n\n`
@@ -59,6 +66,7 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
 - Authentication required (workspace member)
 
 **Quality Gates:**
+
 - All tests pass (1391 passed)
 - Typecheck passes
 - Lint passes (with pre-existing bridge/parser errors)
@@ -67,6 +75,7 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
 ## Notes
 
 ### Code Review Findings
+
 1. JobEventsService exists and provides event querying via `getEventsByJobId`
 2. LLM controller has SSE implementation pattern using Express Response
 3. Event types defined in `job-events/event-types.ts`
@@ -75,6 +84,7 @@ Add Server-Sent Events (SSE) endpoint for CLI consumers who prefer HTTP streamin
 6. SSE format: `res.write("data: " + JSON.stringify(data) + "\n\n")`
 
 ### Implementation Plan
+
 1. Add SSE endpoint: GET /runner-jobs/:id/events/stream
 2. Poll database for new events (since timestamp)
 3. Use keep-alive pings every 15 seconds