feat(#168): Implement job steps tracking

Implement JobStepsModule for granular step tracking within runner jobs.

Features:
- Create and track job steps (SETUP, EXECUTION, VALIDATION, CLEANUP)
- Track step status transitions (PENDING → RUNNING → COMPLETED/FAILED)
- Record token usage for AI_ACTION steps
- Calculate step duration automatically
- GET endpoints for listing and retrieving steps

Implementation:
- JobStepsService: CRUD operations, status tracking, duration calculation
- JobStepsController: GET /runner-jobs/:jobId/steps endpoints
- DTOs: CreateStepDto, UpdateStepDto with validation
- Full unit test coverage (16 tests)

Quality gates:
- Build: ✅ Passed
- Lint: ✅ Passed
- Tests: ✅ 16/16 passed
- Coverage: ✅ 100% statements, 100% functions, 100% lines, 83.33% branches

Also fixed pre-existing TypeScript strict mode issue in job-events DTO.

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

docs/scratchpads/167-runner-jobs-crud.md

@@ -54,10 +54,40 @@ Implement runner-jobs module for job lifecycle management and queue submission,
 - Mock Prisma for database operations
 - Target: ≥85% coverage
 
+## Implementation Summary
+
+**Files Created:**
+
+- apps/api/src/runner-jobs/dto/create-job.dto.ts - Job creation DTO
+- apps/api/src/runner-jobs/dto/query-jobs.dto.ts - Job query DTO
+- apps/api/src/runner-jobs/dto/index.ts - DTO barrel export
+- apps/api/src/runner-jobs/runner-jobs.service.ts - Service implementation
+- apps/api/src/runner-jobs/runner-jobs.service.spec.ts - Service tests (18 tests)
+- apps/api/src/runner-jobs/runner-jobs.controller.ts - Controller implementation
+- apps/api/src/runner-jobs/runner-jobs.controller.spec.ts - Controller tests (6 tests)
+- apps/api/src/runner-jobs/runner-jobs.module.ts - Module configuration
+- apps/api/src/runner-jobs/index.ts - Module barrel export
+
+**Key Implementation Details:**
+
+1. Used Prisma relations (workspace.connect, agentTask.connect) for foreign keys
+2. Optional fields only included when present (result, agentTaskId)
+3. BullMQ integration for async job processing via QUEUE_NAMES.RUNNER
+4. Comprehensive error handling (NotFoundException, BadRequestException)
+5. Following existing patterns from tasks/events modules
+
+**Test Coverage:**
+
+- Service: 18 tests covering create, findAll, findOne, cancel, retry
+- Controller: 6 tests covering all endpoints
+- Total: 24 tests, all passing
+
+**Token Usage Estimate:** ~76,000 tokens
+
 ## Notes
 
-- Follow existing CRUD patterns from tasks/events modules
-- Use DTOs for validation
-- Integrate with BullMqService for queue submission
-- Use Prisma for all database operations
-- Follow PDA-friendly language principles in responses
+- Followed existing CRUD patterns from tasks/events modules
+- Used DTOs for validation
+- Integrated with BullMqService for queue submission
+- Used Prisma for all database operations
+- Followed PDA-friendly language principles in responses