Replace ElevenLabs with local STT and TTS

.env.example

@@ -2,15 +2,23 @@ DISCORD_BOT_TOKEN=
 DISCORD_APPLICATION_ID=
 DISCORD_COMMAND_GUILD_ID=
 
-ELEVENLABS_API_KEY=
-ELEVENLABS_VOICE_ID=
-ELEVENLABS_STT_MODEL=scribe_v2_realtime
-ELEVENLABS_TTS_MODEL=eleven_flash_v2_5
 OLLAMA_BASE_URL=http://localhost:11434
 OLLAMA_MODEL=qwen3:0.6b
 OLLAMA_KEEP_ALIVE=5m
 OLLAMA_NUM_CTX=4096
 
+LOCAL_AI_VENV_PATH=.local-ai/.venv
+LOCAL_AI_CACHE_DIR=.local-ai/cache
+LOCAL_AI_PYTHON=
+LOCAL_STT_MODEL=tiny
+LOCAL_STT_DEVICE=auto
+LOCAL_STT_COMPUTE_TYPE=auto
+LOCAL_STT_BEAM_SIZE=1
+LOCAL_TTS_LANGUAGE=KR
+LOCAL_TTS_SPEAKER=KR
+LOCAL_TTS_DEVICE=auto
+LOCAL_TTS_SPEED=1.12
+
 BOT_DEFAULT_LANGUAGE=ko
 MAX_CONVERSATION_TURNS=12
 LOCAL_AUDIO_SOURCE=