Add brain memory services and APIs

Introduce the backend pieces for brain memory ingestion, routing, and
system telemetry so the new knowledge workflows can project data into a
brain view. The supporting tests lock in the new behavior and keep the
expanded backend surface stable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/services/settings_service.py

@@ -1,9 +1,11 @@
+import copy
 import logging
 from typing import Optional
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from app.models.user import User
 from app.services.auth_service import verify_password, get_password_hash
+from app.logging_utils import summarize_llm_config
 
 logger = logging.getLogger(__name__)
 
@@ -49,9 +51,7 @@ async def update_user_profile(
 
 async def update_llm_config(user_id: str, config: dict, db: AsyncSession) -> dict:
     """更新 LLM 配置"""
-    import copy
-    logger.info(f"update_llm_config called with config keys: {list(config.keys())}")
-    logger.info(f"chat config: {config.get('chat')}")
+    logger.info("update_llm_config called", extra={"details": {"keys": list(config.keys())}})
     result = await db.execute(select(User).where(User.id == user_id))
     user = result.scalar_one_or_none()
     if not user:
@@ -59,7 +59,7 @@ async def update_llm_config(user_id: str, config: dict, db: AsyncSession) -> dic
 
     # 创建深拷贝，避免 SQLAlchemy 变更检测问题
     current = copy.deepcopy(user.llm_config) or {}
-    logger.info(f"current llm_config before update: {current}")
+    logger.info("llm_config before update", extra={"details": summarize_llm_config(current)})
     # 合并配置 - 直接替换整个类型配置列表
     for key, value in config.items():
         if value is not None:
@@ -74,11 +74,11 @@ async def update_llm_config(user_id: str, config: dict, db: AsyncSession) -> dic
                     current[key] = value
             else:
                 current[key] = value
-    logger.info(f"current llm_config after update: {current}")
+    logger.info("llm_config after update", extra={"details": summarize_llm_config(current)})
     user.llm_config = current
     await db.commit()
     await db.refresh(user)
-    logger.info(f"user.llm_config after refresh: {user.llm_config}")
+    logger.info("user.llm_config after refresh", extra={"details": summarize_llm_config(user.llm_config)})
     return current