- Apply cargo fmt to ensure consistent code formatting across CLI modules
- Fix trailing whitespace in documentation comments
- Optimize comment formatting and indentation
- All clippy checks pass with no warnings
- Documentation generates cleanly with strict nightly flags
- All tests continue to pass after formatting changes
- Add extensive module-level documentation for labels_cli with usage examples
- Document complete messages_cli module with Gmail query syntax guide
- Add comprehensive struct and method documentation with safety considerations
- Include detailed parameter explanations and error handling guidance
- Document action types with safety levels and reversibility information
- Add practical usage patterns and safety recommendations
- Include extensive examples of Gmail query syntax and filtering options