```

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/services/chatlog_client.py

@@ -2,6 +2,7 @@ import httpx
 import asyncio
 from typing import List
 from config import settings
+from services.http_client import shared_client
 
 
 class ChatlogHTTPError(RuntimeError):
@@ -21,13 +22,21 @@ class ChatlogClient:
     def __init__(self):
         self.base = settings.chatlog_base_url
         self._contact_db_file = None
+        # 进程级头像缓存：wxid -> url。同一账号下同一 wxid 只查一次 chatlog SQL，
+        # 避免打开群聊时几十个发言人各打一次 /api/v1/db/query 头像查询。
+        self._avatar_cache: dict[str, str] = {}
+
+    def reset_account_cache(self):
+        """账号切换时调用：清掉 contact 库路径与头像缓存，避免显示上一个账号的数据。"""
+        self._contact_db_file = None
+        self._avatar_cache.clear()
 
     async def _get(self, path: str, params: dict, timeout: float = 30.0) -> dict:
         try:
-            async with httpx.AsyncClient(timeout=timeout, trust_env=False) as client:
-                r = await client.get(f"{self.base}{path}", params=params)
-                r.raise_for_status()
-                return r.json()
+            client = shared_client()
+            r = await client.get(f"{self.base}{path}", params=params, timeout=timeout)
+            r.raise_for_status()
+            return r.json()
         except httpx.TimeoutException:
             raise RuntimeError(f"chatlog timeout: GET {path}")
         except httpx.HTTPStatusError as e:
@@ -38,10 +47,10 @@ class ChatlogClient:
 
     async def _post(self, path: str, body: dict, timeout: float = 30.0) -> dict:
         try:
-            async with httpx.AsyncClient(timeout=timeout, trust_env=False) as client:
-                r = await client.post(f"{self.base}{path}", json=body)
-                r.raise_for_status()
-                return r.json()
+            client = shared_client()
+            r = await client.post(f"{self.base}{path}", json=body, timeout=timeout)
+            r.raise_for_status()
+            return r.json()
         except httpx.TimeoutException:
             raise RuntimeError(f"chatlog timeout: POST {path}")
         except httpx.HTTPStatusError as e:
@@ -128,15 +137,16 @@ class ChatlogClient:
 
     async def get_message(self, talker: str, seq: int) -> dict | None:
         try:
-            async with httpx.AsyncClient(timeout=10.0, trust_env=False) as client:
-                r = await client.get(
-                    f"{self.base}/api/v1/chatlog/message",
-                    params={"talker": talker, "seq": seq},
-                )
-                if r.status_code == 404:
-                    return None
-                r.raise_for_status()
-                return r.json()
+            client = shared_client()
+            r = await client.get(
+                f"{self.base}/api/v1/chatlog/message",
+                params={"talker": talker, "seq": seq},
+                timeout=10.0,
+            )
+            if r.status_code == 404:
+                return None
+            r.raise_for_status()
+            return r.json()
         except httpx.TimeoutException:
             raise RuntimeError("chatlog timeout: get_message")
         except Exception as e:
@@ -174,6 +184,11 @@ class ChatlogClient:
 
 
     async def get_avatar_url(self, wxid: str) -> str:
+        if not wxid:
+            return ""
+        cached = self._avatar_cache.get(wxid)
+        if cached is not None:
+            return cached
         if self._contact_db_file is None:
             try:
                 db_list = await self._get("/api/v1/db", {})
@@ -185,15 +200,17 @@ class ChatlogClient:
         safe_wxid = wxid.replace("'", "''")
         sql = f"SELECT small_head_url, big_head_url FROM contact WHERE username='{safe_wxid}' LIMIT 1"
         params = {"group": "contact", "file": self._contact_db_file, "sql": sql}
+        url = ""
         try:
             rows = await self._get("/api/v1/db/query", params, timeout=5.0)
             if rows:
                 url = rows[0].get("small_head_url") or rows[0].get("big_head_url") or ""
-                if url:
-                    return url
         except Exception:
-            pass
-        return ""
+            # 查询失败不写缓存，下次仍可重试
+            return ""
+        # 命中（含确定无头像的空串）都缓存，避免重复查询
+        self._avatar_cache[wxid] = url
+        return url
 
     async def get_db_paths(self) -> dict:
         data = await self._get("/api/v1/db", {}, timeout=10.0)