Per md/38_FLOWCLIENT.md analysis:
- Add _initPromise to serialize concurrent init calls (no duplicate worklet)
- audioContext.resume() before worklet.loadModule
- selectInstrument creates AudioContext + awaits init if not ready
- playNote tries SpessaSynth first, falls back to oscillator on error
- All MIDI commands wrapped in try/catch with oscillator fallback
3dtours
2f2cb3a066