Major update:
- Card-based session layout with colored group indicators
- AI agent: Claude API, DeepSeek API, local keyword search
- Collapsible command panel — more space for agent
- macOS build script (build_mac.sh)
- Updated README with Windows/macOS install instructions
- Config persistence in pca_config.json
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
