chore: prepare v0.4.2 release

This release introduces a major architectural improvement with a pluggable analyzer system while maintaining full backwards compatibility.

Version updates:
- Bump version to 0.4.2 in pyproject.toml
- Update CLAUDE.md with v0.4.2 features and improvements
- Add comprehensive CHANGELOG.md documenting all releases

Key features in v0.4.2:
- Pluggable analyzer architecture with factory pattern
- Standardized AnalysisResult for consistent output
- Language-specific analyzers (Python, JavaScript, Java, Objective-C)
- Improved code quality with PEP 8 compliance
- Performance optimizations with regex pre-compilation
- Better error handling and type safety

The new architecture removes 248 lines of duplicated code while improving maintainability and extensibility for future language support.

Author: johnhuang316

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "code-index-mcp"
-version = "0.4.1"
+version = "0.4.2"
 description = "Code indexing and analysis tools for LLMs using MCP"
 readme = "README.md"
 requires-python = ">=3.10"