- Add /api/set-fundamental and /api/play-freq endpoints to server.py
- Add send_single method to osc_sender.py for sending single frequencies
- Add fundamental frequency input and click handler to path_navigator.html
- Distinguish between click (play) and drag (move) on nodes
- Add osc_receiver.scd for SuperCollider to receive /freq messages
- Add preview mode (p key) to toggle between send/preview behavior
- Arrow keys for navigation with optional send
- Enter sends current chord (only when not in preview mode)
- Jump to chord by number + Enter
- k/K keys for kill soft (15.0) and kill hard (0.0) commands
- Display prev/current/next chords with frequencies to 2 decimals
- Add OSC test receiver for debugging
- Use arrow key escape sequences for left/right navigation