feat: enable local docker demo mode

backend/app/services/adapters/__init__.py

@@ -1,5 +1,7 @@
 """适配器模块 - 供应商平台化架构核心。"""
 
+# Demo adapters
+from app.services.adapters import demo as _demo_adapters  # noqa: F401
 from app.services.adapters.base import AdapterConfig, BaseAdapter
 
 # Image adapters
@@ -15,6 +17,7 @@ from app.services.adapters.text import gemini as _text_gemini_adapter  # noqa: F
 from app.services.adapters.text import openai as _text_openai_adapter  # noqa: F401
 
 # TTS adapters
+from app.services.adapters.tts import edge_tts as _tts_edge_tts_adapter  # noqa: F401
 from app.services.adapters.tts import elevenlabs as _tts_elevenlabs_adapter  # noqa: F401
 from app.services.adapters.tts import minimax as _tts_minimax_adapter  # noqa: F401