docs: mark Phase 0 as completed in testing documentation

- Updated checklist to show completed tasks
- Marked Phase 0 as completed in AI-optimized guide
- GitHub Actions workflow confirmed working

docs/testing-checklist.md

@@ -2,11 +2,12 @@
 
 ## Immediate Actions (Day 1)
 
+- [x] ~~Fix failing tests (Phase 0)~~ ✅ COMPLETED
+- [x] ~~Create GitHub Actions workflow file~~ ✅ COMPLETED
 - [ ] Install Vitest and remove Jest
 - [ ] Create vitest.config.ts
 - [ ] Setup global test configuration
 - [ ] Migrate existing tests to Vitest syntax
-- [ ] Create GitHub Actions workflow file
 - [ ] Setup coverage reporting with Codecov
 
 ## Week 1: Foundation
@@ -22,7 +23,7 @@
 - [ ] Configure test environment variables
 
 ### CI/CD Pipeline
-- [ ] GitHub Actions for test execution
+- [x] ~~GitHub Actions for test execution~~ ✅ COMPLETED
 - [ ] Coverage reporting integration
 - [ ] Performance benchmark tracking
 - [ ] Test result artifacts

docs/testing-strategy-ai-optimized.md

@@ -12,7 +12,7 @@ This testing strategy is optimized for implementation by AI agents like Claude C
 4. **Verification Steps**: Each task includes verification commands
 5. **Error Recovery**: Each section includes troubleshooting steps
 
-## Phase 0: Immediate Fixes (Day 1)
+## Phase 0: Immediate Fixes (Day 1) ✅ COMPLETED
 
 ### Task 0.1: Fix Failing Tests