fix(xss+perf): SearchView XSS消除(无v-html)+room_id索引+pool_recycle

- SearchView.vue: 用 highlightSegments() 返回 {text,hit} 数组替代 v-html+escapeHtml+regex,模板用 <template v-for> + <mark>/<span> 渲染,从结构上消除 XSS 风险(4 处 v-html 全部移除: 消息片段/客户昵称/realName/手机号)
- models.py: Message 新增 ix_message_channel_owner_room_time(channel,owner_account_id,room_id,timestamp),群聊查询过滤 room_id 而非 talker_id,原 talker 索引无法覆盖
- migrations/d8eee96cd017: 新增 room_id 索引的 upgrade/downgrade (offline SQL 已验证)
- base.py + scheduler.py + cli.py: 所有生产 create_async_engine 增加 pool_recycle=3600,在 MySQL wait_timeout(默认 8h)断连前主动回收

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

yunke-server/app/sync/cli.py

@@ -228,7 +228,12 @@ async def _init_db(db_url: str) -> tuple[Any, Any]:
     """
     from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
 
-    engine = create_async_engine(db_url, pool_pre_ping=True, future=True)
+    engine = create_async_engine(
+        db_url,
+        pool_pre_ping=True,
+        pool_recycle=3600,  # recycle before MySQL wait_timeout closes us
+        future=True,
+    )
     async with engine.begin() as conn:
         await conn.run_sync(Base.metadata.create_all)
     session_maker = async_sessionmaker(engine, expire_on_commit=False)