feat: Add comprehensive test coverage assessment system

- Add CoverageAnalyzer class for analyzing functional test coverage against issues
- Intelligent requirement extraction from issue descriptions using regex patterns
- Automatic coverage gap detection with priority classification (critical/important/nice-to-have)
- Smart keyword matching between requirements and existing tests
- Comprehensive CLI interface with make test-coverage NUM=X command
- Detailed recommendations with specific test suggestions and TDD workflow guidance

Features:
- Extracts requirements from issue text patterns (user can, must, should, examples, etc.)
- Analyzes existing test files and methods for coverage keywords
- Calculates coverage percentage based on requirement-to-test matching
- Provides specific test name and file suggestions for gaps
- Prioritizes recommendations by requirement criticality
- Integrates with existing TDD workflow (tdd-start, tdd-add-test)

Usage: make test-coverage NUM=5
Example output shows 28.6% coverage for Issue #5 with specific gap recommendations

🤖 Generated with [Claude Code](https://claude.ai/code)

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

tddai_cli.py

@@ -11,7 +11,7 @@ from pathlib import Path
 sys.path.insert(0, str(Path(__file__).parent))
 
 from tddai import (
-    WorkspaceManager, IssueFetcher, TestGenerator,
+    WorkspaceManager, IssueFetcher, TestGenerator, CoverageAnalyzer,
     WorkspaceStatus, TddaiError
 )
 
@@ -246,6 +246,80 @@ def list_open_issues():
         sys.exit(1)
 
 
+def analyze_coverage(issue_number: int):
+    """Analyze test coverage for a specific issue."""
+    try:
+        analyzer = CoverageAnalyzer()
+        print(f"🔍 Analyzing test coverage for Issue #{issue_number}")
+        print("=" * 50)
+        print()
+
+        assessment = analyzer.analyze_issue_coverage(issue_number)
+
+        print(f"📋 Issue: #{assessment.issue_number} - {assessment.issue_title}")
+        print(f"📊 Coverage: {assessment.coverage_percentage:.1f}%")
+        print()
+
+        # Show requirements analysis
+        print("🎯 Identified Requirements:")
+        if assessment.requirements:
+            for req in assessment.requirements:
+                priority_icon = {"critical": "🚨", "important": "⚠️", "nice-to-have": "💡"}
+                icon = priority_icon.get(req.priority, "📝")
+                print(f"   {icon} [{req.priority.upper()}] {req.category}: {req.description}")
+        else:
+            print("   No specific requirements detected")
+        print()
+
+        # Show existing tests
+        print("🧪 Existing Test Coverage:")
+        issue_related_tests = [t for t in assessment.existing_tests if t.related_issue == issue_number]
+        if issue_related_tests:
+            for test in issue_related_tests:
+                test_count = len(test.test_methods)
+                print(f"   ✅ {test.file_path.name} ({test_count} test methods)")
+                if test.test_methods:
+                    for method in test.test_methods[:3]:  # Show first 3
+                        print(f"      - {method}")
+                    if len(test.test_methods) > 3:
+                        print(f"      - ... and {len(test.test_methods) - 3} more")
+        else:
+            print("   📝 No tests specifically for this issue found")
+            # Show general tests that might be relevant
+            relevant_tests = [t for t in assessment.existing_tests
+                            if any(keyword in ' '.join(t.coverage_keywords)
+                                  for req in assessment.requirements
+                                  for keyword in req.keywords)]
+            if relevant_tests:
+                print("   📋 Potentially relevant tests:")
+                for test in relevant_tests[:3]:
+                    print(f"      📄 {test.file_path.name}")
+        print()
+
+        # Show coverage gaps
+        if assessment.coverage_gaps:
+            print("❌ Coverage Gaps Found:")
+            for gap in assessment.coverage_gaps:
+                priority_icon = {"critical": "🚨", "important": "⚠️", "nice-to-have": "💡"}
+                icon = priority_icon.get(gap.requirement.priority, "📝")
+                print(f"   {icon} Missing: {gap.requirement.description}")
+                print(f"      💡 Suggested test: {gap.suggested_test_name}")
+                print(f"      📄 Suggested file: {gap.suggested_test_file}")
+            print()
+        else:
+            print("✅ No significant coverage gaps detected!")
+            print()
+
+        # Show recommendations
+        print("📝 Recommendations:")
+        for recommendation in assessment.recommendations:
+            print(f"   {recommendation}")
+
+    except TddaiError as e:
+        print(f"❌ Error: {e}")
+        sys.exit(1)
+
+
 def show_issue(issue_number: int):
     """Show detailed issue information."""
     try:
@@ -301,6 +375,9 @@ def main():
     show_parser = subparsers.add_parser('show-issue', help='Show issue details')
     show_parser.add_argument('issue_number', type=int, help='Issue number')
 
+    coverage_parser = subparsers.add_parser('analyze-coverage', help='Analyze test coverage for issue')
+    coverage_parser.add_argument('issue_number', type=int, help='Issue number')
+
     args = parser.parse_args()
 
     if not args.command:
@@ -322,6 +399,8 @@ def main():
             list_open_issues()
         elif args.command == 'show-issue':
             show_issue(args.issue_number)
+        elif args.command == 'analyze-coverage':
+            analyze_coverage(args.issue_number)
     except KeyboardInterrupt:
         print("\n⚠️  Operation cancelled")
         sys.exit(1)