feat: migrate realtime voice service to OpenAI provider pipeline

.env.example

@@ -2,12 +2,35 @@ REALTIME_VOICE_HTTP_HOST=0.0.0.0
 REALTIME_VOICE_HTTP_PORT=8000
 REALTIME_VOICE_AUDIOSOCKET_HOST=0.0.0.0
 REALTIME_VOICE_AUDIOSOCKET_PORT=9092
+REALTIME_VOICE_SAMPLE_RATE_HZ=8000
+
+LLM_PROVIDER=openai
 
 OPENAI_API_KEY=
 OPENAI_BASE_URL=
 OPENAI_LLM_MODEL=gpt-4o-mini
 OPENAI_LLM_SYSTEM_PROMPT=You are a concise voice assistant for a telecom call center. Answer clearly and briefly.
 OPENAI_TIMEOUT_SECONDS=30
+OPENAI_STT_MODEL=whisper-1
+OPENAI_STT_LANGUAGE=ru
+OPENAI_STT_TIMEOUT_SECONDS=30
+
+OLLAMA_BASE_URL=http://host.docker.internal:11434
+OLLAMA_LLM_MODEL=qwen2.5:1.5b
+OLLAMA_TIMEOUT_SECONDS=20
+OLLAMA_LLM_TEMPERATURE=0.3
+OLLAMA_LLM_SYSTEM_PROMPT=Ты Айнур, голосовой ИИ-оператор. Всегда отвечай только на русском, коротко и по делу.
+OLLAMA_LLM_MAX_CONTEXT_MESSAGES=4
+OLLAMA_LLM_NUM_PREDICT=64
+OLLAMA_LLM_NUM_CTX=1024
+
+STT_PROVIDER=openai
+STT_FALLBACK_PROVIDER=elevenlabs
+STT_PROMPT=Это разговор на русском языке, но могут встречаться казахские имена: Айбын, Магжан, Бауыржан, Асель.
+TTS_PROVIDER=elevenlabs
+
+ENABLE_AUDIO_DUMP=false
+AUDIO_DUMP_DIR=debug_audio
 
 ELEVENLABS_API_KEY=
 ELEVENLABS_API_BASE=https://api.elevenlabs.io
@@ -15,13 +38,23 @@ ELEVENLABS_TTS_VOICE_ID=
 ELEVENLABS_TTS_MODEL_ID=eleven_flash_v2_5
 ELEVENLABS_TTS_LANGUAGE_CODE=ru
 ELEVENLABS_TTS_OUTPUT_FORMAT=pcm_16000
+ELEVENLABS_TTS_SPEED=1.0
 ELEVENLABS_STT_MODEL_ID=scribe_v2
-ELEVENLABS_STT_LANGUAGE_CODE=
+ELEVENLABS_STT_REALTIME_MODEL_ID=scribe_v2_realtime
+ELEVENLABS_STT_LANGUAGE_CODE=ru
+ELEVENLABS_STT_USE_REALTIME=true
+ELEVENLABS_STT_ALLOW_BATCH_FALLBACK=true
 ELEVENLABS_TIMEOUT_SECONDS=30
 
+YANDEX_STT_API_KEY=
+YANDEX_STT_IAM_TOKEN=
+YANDEX_STT_FOLDER_ID=
+YANDEX_STT_LANGUAGE=ru-RU
+YANDEX_STT_TOPIC=general
+
 VAD_THRESHOLD=0.5
 VAD_NEGATIVE_THRESHOLD=
-VAD_SILENCE_TIMEOUT_MS=1600
+VAD_SILENCE_TIMEOUT_MS=550
 VAD_SPEECH_PAD_MS=64
 VAD_MIN_SPEECH_DURATION_MS=0
 VAD_USE_ONNX=false