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.

tests/gateway/test_voice_command.py

@@ -1928,3 +1928,38 @@ class TestVoiceChannelAwareness:
     def test_context_empty_when_not_connected(self):
         adapter = self._make_adapter()
         assert adapter.get_voice_channel_context(111) == ""
+
+
+# ---------------------------------------------------------------------------
+# Bugfix: disconnect() must clean up voice state
+# ---------------------------------------------------------------------------
+
+
+class TestDisconnectVoiceCleanup:
+    """Bug: disconnect() left voice dicts populated after closing client."""
+
+    @pytest.mark.asyncio
+    async def test_disconnect_clears_voice_state(self):
+        from unittest.mock import AsyncMock
+
+        adapter = MagicMock()
+        adapter._voice_clients = {111: MagicMock(), 222: MagicMock()}
+        adapter._voice_receivers = {111: MagicMock(), 222: MagicMock()}
+        adapter._voice_listen_tasks = {111: MagicMock(), 222: MagicMock()}
+        adapter._voice_timeout_tasks = {111: MagicMock(), 222: MagicMock()}
+        adapter._voice_text_channels = {111: 999, 222: 888}
+
+        async def mock_leave(guild_id):
+            adapter._voice_receivers.pop(guild_id, None)
+            adapter._voice_listen_tasks.pop(guild_id, None)
+            adapter._voice_clients.pop(guild_id, None)
+            adapter._voice_timeout_tasks.pop(guild_id, None)
+            adapter._voice_text_channels.pop(guild_id, None)
+
+        for gid in list(adapter._voice_clients.keys()):
+            await mock_leave(gid)
+
+        assert len(adapter._voice_clients) == 0
+        assert len(adapter._voice_receivers) == 0
+        assert len(adapter._voice_listen_tasks) == 0
+        assert len(adapter._voice_timeout_tasks) == 0