SPEC-AUTH-001/REQ-SEC-1: Password hashing with bcrypt
├── Implementation Evidence:
│   ├── Code: src/auth/signup.ts:23 (bcrypt.hash call)
│   ├── Code: src/auth/password-reset.ts:34 (bcrypt.hash call)
│   ├── Tests: tests/auth/security.test.ts:15-28
│   └── Config: config/security.js:12 (bcrypt cost factor)
├── Coverage: 100% (all locations implementing requirement)
└── Status: ✅ Verified Complete

// Implements: SPEC-AUTH-001/REQ-SEC-1
// Purpose: Hash passwords with bcrypt for secure storage
// Context: Required for user authentication security
const passwordHash = await bcrypt.hash(password, 12);

// This code has no spec traceability:
function obscureUtility(input) {
  return input.split('_').reverse().join('-');
}
// ❌ No @spec comment = potential dead code

SPEC-AUTH-001/WORKFLOW-AUTH-1: User Signup Flow
├── Step 1: UI Input → COMPONENT-AUTH-1 (signup form)
├── Step 2: Validation → API-AUTH-1 (email validation)
├── Step 3: Account Creation → MODEL-USER (database record)
├── Step 4: Email Verification → INT-EMAIL-1 (send service)
└── Dependencies:
    ├── SPEC-DB-001: User table schema
    ├── SPEC-EMAIL-001: Email service integration
    └── SPEC-VALID-001: Input validation patterns

// @spec SPEC-ID/REQUIREMENT-ID [Description]
// @context [Why this implementation choice]
// @dependencies [Related requirements]

// @spec SPEC-AUTH-001/API-AUTH-1
// @context Implements POST /auth/signup with validation and rate limiting
// @dependencies SPEC-AUTH-001/REQ-SEC-1 (password hashing)
export async function signup(req: Request, res: Response) {
  // @spec SPEC-AUTH-001/REQ-VAL-1 Email format validation
  if (!isValidEmail(req.body.email)) {
    return res.status(400).json({ error: 'Invalid email' });
  }
  
  // @spec SPEC-AUTH-001/REQ-SEC-1 Password hashing with bcrypt
  const hash = await bcrypt.hash(req.body.password, 12);
  
  // @spec SPEC-AUTH-001/MODEL-USER User record creation
  const user = await User.create({
    email: req.body.email,
    password_hash: hash
  });
}

// @spec SPEC-AUTH-001/COMPONENT-AUTH-1
// @context Login form with real-time validation
// @dependencies SPEC-AUTH-001/REQ-UI-1 (form validation patterns)
export function LoginForm() {
  const [email, setEmail] = useState('');
  const [errors, setErrors] = useState({});

  // @spec SPEC-AUTH-001/REQ-UI-2 Real-time email validation
  const validateEmail = (value: string) => {
    if (!isValidEmail(value)) {
      setErrors(prev => ({ ...prev, email: 'Invalid email format' }));
    }
  };

  // @spec SPEC-AUTH-001/REQ-UI-3 Submit button state management
  const isSubmitDisabled = !email || !password || Object.keys(errors).length > 0;
}

-- @spec SPEC-AUTH-001/MODEL-USER
-- @context User table with authentication fields
-- @dependencies SPEC-DB-001 (base table patterns)
CREATE TABLE users (
  -- @spec SPEC-AUTH-001/REQ-DATA-1 UUID primary key
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  
  -- @spec SPEC-AUTH-001/REQ-DATA-2 Unique email constraint
  email VARCHAR(255) UNIQUE NOT NULL,
  
  -- @spec SPEC-AUTH-001/REQ-SEC-1 Bcrypt password hash storage
  password_hash VARCHAR(255) NOT NULL,
  
  created_at TIMESTAMP DEFAULT NOW(),
  updated_at TIMESTAMP DEFAULT NOW()
);

-- @spec SPEC-AUTH-001/REQ-PERF-1 Email lookup optimization
CREATE INDEX idx_users_email ON users(email);

// @spec SPEC-AUTH-001/TEST-AUTH-1
// @context End-to-end signup workflow testing
// @dependencies SPEC-AUTH-001/WORKFLOW-AUTH-1 (complete signup flow)
describe('User Signup Workflow', () => {
  
  // @spec SPEC-AUTH-001/REQ-PERF-1 Signup performance requirement
  it('completes signup within 2 seconds', async () => {
    const startTime = Date.now();
    
    await signupUser({
      email: 'test@example.com',
      password: 'SecurePass123!'
    });
    
    const duration = Date.now() - startTime;
    expect(duration).toBeLessThan(2000);
  });

  // @spec SPEC-AUTH-001/REQ-SEC-1 Password security validation
  it('hashes passwords with bcrypt', async () => {
    const user = await signupUser({
      email: 'security@test.com',
      password: 'TestPassword123!'
    });
    
    // Verify password is hashed (not stored in plain text)
    expect(user.password_hash).not.toBe('TestPassword123!');
    expect(user.password_hash.startsWith('$2b$12$')).toBe(true);
  });
});

// @spec SPEC-AUTH-001
// @context Complete authentication system implementation
// @architecture Clean Architecture pattern with separation of concerns
export class AuthenticationService {
  
  // @spec SPEC-AUTH-001/API-AUTH-1 User signup endpoint
  async signup(request: SignupRequest): Promise<SignupResult> {
    // Implementation delegates to specific requirement handlers
  }
}

// @spec SPEC-AUTH-001/REQ-SEC-1
// @context Password hashing implementation with bcrypt
// @security Uses cost factor 12 for future-proof protection
private async hashPassword(password: string): Promise<string> {
  return bcrypt.hash(password, 12);
}

// @spec SPEC-AUTH-001/REQ-PERF-1 Performance optimization
const user = await User.findOne({ email }); // Indexed lookup for <100ms query
if (!user) {
  // @spec SPEC-AUTH-001/REQ-SEC-2 Timing attack prevention
  await bcrypt.hash('dummy', 12); // Constant-time response
  return null;
}

SPEC-AUTH-001 Implementation Status:
├── Total Requirements: 23
├── Implemented: 21 (91.3%)
├── In Progress: 2 (8.7%)
├── Not Started: 0 (0%)
└── Coverage Grade: A- (90%+ implemented)

Detailed Breakdown:
├── Workflows: 3/3 (100%) ✅
├── Data Models: 2/2 (100%) ✅  
├── API Endpoints: 4/5 (80%) 🔄
├── UI Components: 3/3 (100%) ✅
├── Security Requirements: 7/7 (100%) ✅
├── Performance Requirements: 2/3 (67%) 🔄
└── Test Requirements: 0/0 (N/A) ⚫

Source Code Analysis:
├── Total Lines of Code: 2,847
├── Spec-Traced Lines: 2,103 (73.9%)
├── Orphaned Code: 744 lines (26.1%)
└── Coverage Grade: C+ (70-80% traced)

Orphaned Code Locations:
├── src/utils/legacy.ts: 234 lines (utility functions)
├── src/auth/deprecated.ts: 156 lines (old implementation)
├── src/helpers/misc.ts: 89 lines (helper functions)
└── tests/manual/: 265 lines (manual test scripts)

Action Required:
├── Archive or document legacy code
├── Add @spec comments to utility functions
└── Remove or trace deprecated implementations

// Generated coverage report
interface CoverageReport {
  spec: {
    total_requirements: number;
    implemented: number;
    coverage_percentage: number;
    missing_requirements: SpecRequirement[];
  };
  code: {
    total_lines: number;
    traced_lines: number;
    coverage_percentage: number;
    orphaned_files: string[];
  };
  quality: {
    grade: 'A+' | 'A' | 'B+' | 'B' | 'C+' | 'C' | 'D' | 'F';
    recommendations: string[];
    action_items: ActionItem[];
  };
}

Coverage Dashboard (Live):
┌─────────────────────────────────────────┐
│ Specification Traceability Status      │
├─────────────────────────────────────────│
│ Requirements Implemented: 21/23 (91%)  │
│ Code Coverage: 2,103/2,847 lines (74%) │
│ Overall Grade: B+ (Improving ↗)        │
├─────────────────────────────────────────│
│ Recent Changes:                         │
│ ✅ Added REQ-PERF-2 implementation     │
│ 🔄 Working on API-AUTH-5 endpoint      │
│ ⚠️  Orphaned code detected in utils/    │
└─────────────────────────────────────────┘

// Verify all @spec comments reference valid requirements
interface SpecVerification {
  valid_references: number;
  invalid_references: InvalidReference[];
  orphaned_requirements: string[];
  duplicate_implementations: DuplicateRef[];
}

interface InvalidReference {
  file: string;
  line: number;
  spec_id: string;
  error: 'spec_not_found' | 'requirement_not_found' | 'malformed_id';
}

# CI Pipeline: Traceability Validation
name: Verify Specification Traceability

on: [push, pull_request]

jobs:
  traceability:
    runs-on: ubuntu-latest
    steps:
      - name: Check Spec References
        run: |
          # Verify all @spec comments reference valid requirements
          mod validate-traces --strict
          
      - name: Coverage Requirements
        run: |
          # Fail CI if coverage drops below threshold
          mod coverage-check --min-spec=90 --min-code=75
          
      - name: Orphaned Code Detection
        run: |
          # Report but don't fail on orphaned code
          mod detect-orphans --report-only

Traceability Review Process:
├── 1. Automated Analysis
│   ├── Scan all @spec comments for validity
│   ├── Calculate coverage percentages
│   └── Identify orphaned code sections
├── 2. Peer Review
│   ├── Review traceability in pull requests
│   ├── Validate spec references make sense
│   └── Check for missing requirements
├── 3. Spec Owner Approval
│   ├── Product owner verifies requirement accuracy
│   ├── Architect approves technical implementation
│   └── QA validates test coverage completeness
└── 4. Continuous Monitoring
    ├── Weekly coverage reports
    ├── Monthly traceability audits
    └── Quarterly spec alignment reviews

// IDE Plugin: Live Traceability Checking
interface LiveValidation {
  on_save: () => {
    // Validate @spec comments in saved file
    // Highlight invalid references in editor
    // Update coverage metrics in sidebar
  };
  
  on_edit: (line: string) => {
    // Suggest spec IDs for new code
    // Auto-complete requirement references
    // Show related specifications inline
  };
}

// Background Process: Traceability Maintenance
interface MaintenanceBot {
  daily_tasks: [
    'validate_all_spec_references',
    'update_coverage_reports', 
    'identify_new_orphaned_code',
    'notify_teams_of_missing_traces'
  ];
  
  weekly_tasks: [
    'generate_comprehensive_coverage_report',
    'identify_specification_gaps',
    'suggest_traceability_improvements'
  ];
  
  monthly_tasks: [
    'audit_requirement_completeness',
    'review_orphaned_code_justifications',
    'update_traceability_standards'
  ];
}

// New Feature Development Workflow
1. Write specification with clear requirement IDs
2. Generate implementation tasks with spec links
3. Implement code with @spec traceability comments
4. Write tests that verify specific requirements
5. Review traceability before merge approval

// Bug Fix Workflow
1. Identify which requirement the bug violates
2. Update specification if requirement was unclear
3. Fix code with clear @spec reference to requirement
4. Add test to verify requirement compliance
5. Update traceability documentation

// Refactoring Workflow
1. Identify all requirements affected by refactoring
2. Preserve @spec comments through code changes
3. Update traceability if implementation approach changes
4. Verify all requirements still satisfied after refactor
5. Update specification if architecture changes

Traceability Review Checklist:
- [ ] All new code includes @spec comments
- [ ] @spec references point to valid requirements
- [ ] Implementation matches specification intent
- [ ] Tests verify the stated requirements
- [ ] No orphaned code introduced
- [ ] Coverage metrics maintained or improved

New Team Member Traceability Training:
1. Understand specification structure and IDs
2. Learn @spec comment format and standards
3. Practice reading traceability in existing code
4. Review coverage reports and quality metrics
5. Shadow experienced developer on traced implementation

Release Readiness Criteria:
- [ ] 90%+ requirement implementation coverage
- [ ] 80%+ code traceability coverage
- [ ] All @spec references validated
- [ ] Critical requirements have test coverage
- [ ] Orphaned code documented or removed
- [ ] Traceability audit completed

interface TraceabilityMetrics {
  weekly: {
    coverage_trend: number; // percentage change
    new_orphaned_lines: number;
    invalid_references_fixed: number;
    requirements_completed: number;
  };
  
  monthly: {
    quality_grade_progression: string;
    team_compliance_rate: number;
    specification_accuracy: number;
    audit_findings: AuditFinding[];
  };
}

Quarterly Traceability Review:
1. Analyze coverage trends and quality metrics
2. Identify common traceability failure patterns
3. Update standards and tooling based on learnings
4. Train team on improved practices
5. Set targets for next quarter improvement