feat: land page aggregate and phase7 document ai mainline

- 收口 page aggregate 读取、本地状态与命令客户端\n- 接入 phase7 document ai sidecar 与前端编排入口\n- 更新 architecture 与 design 状态迁移

wolai-backend/app/config.py

@@ -22,6 +22,9 @@ class Settings(BaseSettings):
     redis_url: str = "redis://localhost:6379/0"
     frontend_url: str = "http://localhost:3000"
     openai_api_key: str = ""
+    mnote_ai_default_model: str = ""
+    mnote_ai_orchestrator_api_key: str = ""
+    openai_agents_session_db_path: str = ""
     lightrag_db_url: str = ""
     lightrag_collection: str = "wolai-docs"