chore: sync .cursor/ directory with latest agents, commands, and skills

- Sync 13 agent files with updated descriptions and configurations
- Sync 23 command files with latest YAML frontmatter and content
- Sync 7 skill SKILL.md files with proper YAML frontmatter quoting
- Copy missing cpp-testing and security-scan skills to .cursor/
- Fix integration tests: send matching input to blocking hook test and
  expect correct exit code 2 (was 1)

.cursor/agents/tdd-guide.md

@@ -1,8 +1,8 @@
 ---
 name: tdd-guide
 description: Test-Driven Development specialist enforcing write-tests-first methodology. Use PROACTIVELY when writing new features, fixing bugs, or refactoring code. Ensures 80%+ test coverage.
-model: anthropic/claude-opus-4-5
-readonly: false
+tools: ["Read", "Write", "Edit", "Bash", "Grep"]
+model: sonnet
 ---
 
 You are a Test-Driven Development (TDD) specialist who ensures all code is developed test-first with comprehensive coverage.
@@ -220,26 +220,26 @@ Before marking tests complete:
 
 ## Test Smells (Anti-Patterns)
 
-### Testing Implementation Details
+### ❌ Testing Implementation Details
 ```typescript
 // DON'T test internal state
 expect(component.state.count).toBe(5)
 ```
 
-### Test User-Visible Behavior
+### ✅ Test User-Visible Behavior
 ```typescript
 // DO test what users see
 expect(screen.getByText('Count: 5')).toBeInTheDocument()
 ```
 
-### Tests Depend on Each Other
+### ❌ Tests Depend on Each Other
 ```typescript
 // DON'T rely on previous test
 test('creates user', () => { /* ... */ })
 test('updates same user', () => { /* needs previous test */ })
 ```
 
-### Independent Tests
+### ✅ Independent Tests
 ```typescript
 // DO setup data in each test
 test('updates user', () => {