Add Pending_Query class and voice interaction improvements

- lib/pending-query.mjs: new state machine for query accumulation
  wake word, silence timer, send/cancel/pause/resume, instant dispatch,
  mode toggle (always listen / stop listening), mode query
- query-demo.mjs: refactored to use Pending_Query; wake word on by default
  with silence timer; chimes for dispatch/working/cancel/activate
- tts-server.mjs: track last_speak_at, expose /activity endpoint,
  chime playback via Python queue (soundfile + librosa), preload on startup
- chatterbox-server.py: chime and preload commands via stdin protocol
- lib/chatterbox-tts.mjs: play_chime and preload_chime methods
- test-chime.mjs: simple chime test script
- voices.yaml: configured ready/cancel/working/dispatch chimes
- CLEANUP-PLAN.md: updated with current state, command vocabulary, future plans

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

voices.yaml

@@ -56,7 +56,10 @@ voices:
 # System event chimes — map event name to audio file path.
 # Falls back to chimes/<name>.wav or .ogg if not listed here.
 chimes:
-#  ready:    /home/devilholk/sounds/trek-chirp.wav
+  ready:     /home/devilholk/Documents/ready.ogg
+  cancel:    /home/devilholk/Documents/abort.ogg
+  working:   /home/devilholk/Documents/working.ogg
+  dispatch:  /home/devilholk/Documents/dispatch.ogg
 #  dispatch: /home/devilholk/sounds/trek-send.wav
 #  cancel:   /home/devilholk/sounds/cancel.ogg
 #  error:    /home/devilholk/sounds/error.ogg