fix: voice pipeline hardening — 7 bug fixes with tests

1. Anthropic + ElevenLabs TTS silence: forward full response to TTS
   callback for non-streaming providers (choices first, then native
   content blocks fallback).

2. Subprocess timeout kill: play_audio_file now kills the process on
   TimeoutExpired instead of leaving zombie processes.

3. Discord disconnect cleanup: leave all voice channels before closing
   the client to prevent leaked state.

4. Audio stream leak: close InputStream if stream.start() fails.

5. Race condition: read/write _on_silence_stop under lock in audio
   callback thread.

6. _vprint force=True: show API error, retry, and truncation messages
   even during streaming TTS.

7. _refresh_level lock: read _voice_recording under _voice_lock.

cli.py

@@ -3611,7 +3611,11 @@ class HermesCLI:
 
         # Periodically refresh prompt to update audio level indicator
         def _refresh_level():
-            while self._voice_recording:
+            while True:
+                with self._voice_lock:
+                    still_recording = self._voice_recording
+                if not still_recording:
+                    break
                 if hasattr(self, '_app') and self._app:
                     self._app.invalidate()
                 time.sleep(0.15)