feat: 添加 s2s 实时语音 WebSocket 地址支持，并更新相关配置

backend/app/config.py

@@ -82,6 +82,11 @@ class Settings:
     S2S_BUILD_RETRIES = int(_env("DPM_S2S_BUILD_RETRIES", "4"))
     S2S_BUILD_RETRY_DELAY = float(_env("DPM_S2S_BUILD_RETRY_DELAY", "10"))
     S2S_LOG_LEVEL = _env("DPM_S2S_LOG_LEVEL", "INFO").upper()
+    # 对外可访问的 s2s 实时语音 WS 地址（供 /api/config 下发；DPM_VOICE_WS 可显式覆盖）
+    S2S_WS_URL = _env(
+        "DPM_VOICE_WS",
+        f"ws://{_env('MQTT_PUBLIC_HOST', _env('MQTT_BROKER_HOST', 'localhost'))}:8765/v1/realtime",
+    )
     # 语音助手基础提示词（.env 设 DPM_S2S_INSTRUCTIONS 可覆盖；知识库内容由 rag 自动拼接）
     S2S_INSTRUCTIONS = _env(
         "DPM_S2S_INSTRUCTIONS",

backend/app/routers.py

@@ -127,6 +127,7 @@ async def runtime_config():
         "mqtt_url": ws,
         "mqtt_username": settings.MQTT_USERNAME or "",
         "mqtt_password": settings.MQTT_PASSWORD or "",
+        "voice_url": settings.S2S_WS_URL,
         "api_base": f"http://{host}:{settings.PORT}",
         "broker_host": host,
     }