Add comprehensive C and C++ project analysis including header classification (stdlib, POSIX, external), compiler flag suggestions, and Makefile generation. Extend DependencyResolver with C library package mappings for debian, fedora, arch, and brew platforms. Update ProjectAnalyzer with LANGUAGE_EXTENSIONS and BUILD_FILES mappings, rename python_version to language_version, and add build_system and compiler_flags fields to AnalysisResult. Enhance SafeCommandExecutor with incomplete argument detection for find, grep, and sed commands. Add metadata field to OperationResult in TransactionalFileSystem and fix hidden directory validation logic. Bump version to 1.69.0 and promote development status to Production/Stable.
- Eliminated the OPENROUTER_API_KEY environment variable requirement from README.md and help_docs.py
- Updated rp/core/assistant.py to fall back to DEFAULT_API_KEY when no key is provided
- Added robust empty response and JSON decode error handling in rp/core/api.py
- Bumped version from 1.65.1 to 1.67.0 in pyproject.toml
- Updated CHANGELOG.md with version 1.67.0 entry documenting the API key removal
