Standardize project name to lowercase 'g3' throughout documentation,
comments, and configuration files. Environment variables (G3_*) are
unchanged as they follow the uppercase convention.
- Add g3-computer-control crate to architecture documentation
- Document all 13 tools including computer control and TODO management
- Add context thinning feature documentation (50-80% thresholds)
- Update tool ecosystem section with complete tool list
- Remove broken link to non-existent COMPUTER_CONTROL.md
- Update workspace count from 5 to 6 crates
- Add platform-specific implementation details for computer control
- Document OCR support via Tesseract
- Clarify setup instructions for computer control features
