0.0.4

• Added new get_changelog tool: fetches and parses a targeted version range from a package's CHANGELOG.md to provide precise migration context.
• Enhanced error handling across ArchivePubService and GithubPubService to provide descriptive error messages for package/file discovery failures.
• Implemented ChangelogParser utility with robust regex-based extraction and fuzzy version matching.
• Added new search_package_code tool: performs a case-insensitive keyword or regex search across a package's internal lib/ source files, returning file paths, 1-based line numbers, and ±3-line context snippets.
• Generated files (.g.dart, .freezed.dart, .gr.dart, .mocks.dart, .config.dart) are automatically excluded from search results to reduce noise.
• Search results are capped at 15 matches to prevent LLM context overflow.
• Updated README to document the new tools including parameter references and real output examples.