feat: C3.9 documentation extraction, AI enhancement optimization, and C# support

Complete implementation of C3.9, granular AI enhancement control, performance optimizations, and bug fixes.

Features:
- C3.9 Project Documentation Extraction (markdown files)
- Granular AI enhancement control (--enhance-level 0-3)
- C# test extraction support
- 6-12x faster LOCAL mode with parallel execution
- Auto-enhancement UX improvements
- LOCAL mode fallback for all AI enhancements

Bug Fixes:
- C# language support
- Config type field compatibility
- LocalSkillEnhancer import

Documentation:
- Updated CHANGELOG.md
- Updated CLAUDE.md
- Removed client-specific files

Tests: All 1,257 tests passing
Critical linter errors: Fixed

tests/test_analyze_command.py

@@ -74,7 +74,8 @@ class TestAnalyzeSubcommand(unittest.TestCase):
             "--skip-patterns",
             "--skip-test-examples",
             "--skip-how-to-guides",
-            "--skip-config-patterns"
+            "--skip-config-patterns",
+            "--skip-docs"
         ])
         self.assertTrue(args.skip_api_reference)
         self.assertTrue(args.skip_dependency_graph)
@@ -82,6 +83,7 @@ class TestAnalyzeSubcommand(unittest.TestCase):
         self.assertTrue(args.skip_test_examples)
         self.assertTrue(args.skip_how_to_guides)
         self.assertTrue(args.skip_config_patterns)
+        self.assertTrue(args.skip_docs)
 
     def test_backward_compatible_depth_flag(self):
         """Test that deprecated --depth flag still works."""