feat(repository): add language statistics analysis feature

- Remove data directory from gitignore to include language data
- Add build script to parse linguist languages.yml and generate static mappings
- Include serde and serde_yml dependencies for YAML parsing
- Add lang_stats module with language detection and statistics calculation
- Generate protobuf definitions for language statistics API endpoints
- Implement GetLanguageStats RPC endpoint in repository server
- Add comprehensive test suite for language statistics functionality
- Include extension and filename based language detection logic
- Implement binary file classification and group resolution features

.gitignore

@@ -5,4 +5,3 @@
 .project
 .settings
 .DS_Store
-data