- New useVoiceInput hook (lib/voice.ts): "server" records with MediaRecorder
and sends to /voice/transcribe, "browser" keeps the live recognition,
"off" or missing browser support hides the microphone.
- Quick dump bar, mobile capture sheet and hold-to-record use it; live
waves from the real input level (VoiceWave) and "Wird erkannt…".
- Recordings stop after STT_MAX_SECONDS.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>