Added technotes/API-Diagnostic-Commands.md with:
- Complete curl examples for all API endpoints
- SSH + docker exec one-liners for easy testing
- Organized by category (health, contacts, device, channels, messages, DM, settings, archives)
- Example JSON responses for each endpoint
- Useful one-liners with jq for advanced queries
- Quick troubleshooting section with logs and health checks
- Notes on ports, methods, and response times
This serves as a quick reference for debugging and testing the mc-webui API.
