```

feat(api): 添加万川平台模型配置获取和同步功能

- 新增 getWanchuanModelConfig 函数，按模型编码获取平台模型配置
- 新增 syncWanchuanModelToSettings 函数，从万川平台拉取模型配置并写入后端 AI 设置
- 支持按用途分多个模型编码（generic/vision/voice）分别同步配置
- 配置失败时跳过对应字段，不影响其他模型同步

feat(settings): 重构AI模型配置界面支持多模块分组

- 将AI配置按话题分析、报告生成、视觉、语音四个模块分组展示
- 每个模块独立配置接口地址、密钥和模型名称
- 添加从万川平台获取配置的按钮和同步功能
- 优化配置状态指示和错误提示信息

refactor(config): 扩展AI配置支持独立的语音视觉报告网关

- 新增 voice_base_url/voice_api_key 配置项
- 新增 vision_base_url/vision_api_key 配置项
- 新增 summary_base_url/summary_api_key 配置项
- 留空时回退到 ai_base_url/ai_api_key 兼容单网关场景

refactor(http): 统一使用共享HTTP客户端减少连接开销

- 替换各处 httpx.AsyncClient 为 shared_client
- 在 lifespan 中正确关闭共享客户端资源
- 优化 get_current_wxid 和 health 检查中的HTTP请求

refactor(ai): 按用途缓存AI客户端支持不同网关配置

- 重构 get_openai_client 支持按(base_url, api_key)缓存
- 新增 get_client_for 函数按用途获取对应客户端
- 支持语音、视觉、报告等不同用途使用独立网关和密钥
```

chatlog_fastAPI/database.py

@@ -1,10 +1,10 @@
 import aiosqlite
 import asyncio
-import httpx
 import logging
 import time
 from pathlib import Path
 from config import settings
+from services.http_client import shared_client
 
 log = logging.getLogger(__name__)
 
@@ -44,35 +44,35 @@ async def get_current_wxid(force: bool = False):
         return _resolved_wxid
     # 重新解析当前 wxid
     base = settings.chatlog_base_url
-    async with httpx.AsyncClient(trust_env=False, timeout=10.0) as client:
-        try:
-            r = await client.get(f"{base}/api/v1/chatlog", params={"talker": "filehelper", "limit": 100, "time": "1970-01-01,2099-12-31", "format": "json"})
-            if r.status_code == 200:
-                data = r.json()
-                for msg in data.get("items", []):
-                    if msg.get("isSelf"):
-                        _resolved_wxid = msg.get("sender")
-                        _wxid_last_resolved = time.time()
-                        return _resolved_wxid
-        except Exception:
-            pass
+    client = shared_client()
+    try:
+        r = await client.get(f"{base}/api/v1/chatlog", params={"talker": "filehelper", "limit": 100, "time": "1970-01-01,2099-12-31", "format": "json"}, timeout=10.0)
+        if r.status_code == 200:
+            data = r.json()
+            for msg in data.get("items", []):
+                if msg.get("isSelf"):
+                    _resolved_wxid = msg.get("sender")
+                    _wxid_last_resolved = time.time()
+                    return _resolved_wxid
+    except Exception:
+        pass
 
-        try:
-            r = await client.get(f"{base}/api/v1/chatroom", params={"limit": 10, "format": "json"})
-            if r.status_code == 200:
-                rooms = r.json().get("items", [])
-                for room in rooms:
-                    room_id = room.get("name")
-                    r2 = await client.get(f"{base}/api/v1/chatlog", params={"talker": room_id, "limit": 50, "time": "1970-01-01,2099-12-31", "format": "json"})
-                    if r2.status_code == 200:
-                        data2 = r2.json()
-                        for msg in data2.get("items", []):
-                            if msg.get("isSelf"):
-                                _resolved_wxid = msg.get("sender")
-                                _wxid_last_resolved = time.time()
-                                return _resolved_wxid
-        except Exception:
-            pass
+    try:
+        r = await client.get(f"{base}/api/v1/chatroom", params={"limit": 10, "format": "json"}, timeout=10.0)
+        if r.status_code == 200:
+            rooms = r.json().get("items", [])
+            for room in rooms:
+                room_id = room.get("name")
+                r2 = await client.get(f"{base}/api/v1/chatlog", params={"talker": room_id, "limit": 50, "time": "1970-01-01,2099-12-31", "format": "json"}, timeout=10.0)
+                if r2.status_code == 200:
+                    data2 = r2.json()
+                    for msg in data2.get("items", []):
+                        if msg.get("isSelf"):
+                            _resolved_wxid = msg.get("sender")
+                            _wxid_last_resolved = time.time()
+                            return _resolved_wxid
+    except Exception:
+        pass
     if force:
         reset_wxid_cache()
     return "default"
@@ -85,6 +85,10 @@ async def update_db_path(force: bool = False):
         log.info(f"Switching database to {new_path}")
         _current_db_path = new_path
         await init_db(new_path)
+        # 账号切换：清掉 chatlog 客户端的 contact 库路径与头像缓存，避免显示上一个账号的头像。
+        # 局部导入避免潜在的模块循环引用。
+        from services.chatlog_client import chatlog_client
+        chatlog_client.reset_account_cache()
     return _current_db_path
 
 def get_active_db_path():