私密/公开互斥兜底 + 智能体搜索按显示后名称匹配 + 多处小修

- 后端 update_agent / set_agent_private 增加兜底：is_private=true 时强制
  published=false，杜绝同时落在公开+私密两个广场的灰色态
- agent-card 编辑弹窗暴露 editIsPrivate 开关，与公开发布开关在前端互斥校验
- agent-gallery 智能体模糊搜索改为前端针对 desensitize() 后的名字比对，
  解决脱敏显示与原始名字不一致导致看似搜索失效的问题
- useUpdateAgent 在 onSuccess 立刻把新数据 patch 进所有 ["agents"] 列表
  缓存，卡片在后台 refetch 完成前先行 re-render，避免「切换私密/发布后
  好像没反应」的体感延迟
- useGlobalShortcuts 对 event.key 为 undefined（IME 合成 / 扩展注入）做
  容错，否则会抛 TypeError 把后续所有快捷键吃掉

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

offline-backend-20260512/backend/app/gateway/routers/agents.py

@@ -495,6 +495,13 @@ async def update_agent(agent_id: str, request: AgentUpdateRequest, http_request:
             update_data["published"] = bool(request.published)
         if "is_private" in fields_set:
             update_data["is_private"] = bool(request.is_private)
+        # Mutual exclusion: an agent moved into the private square cannot
+        # also be publicly published. Force ``published=false`` whenever the
+        # same request sets ``is_private=true``, even if the client forgot
+        # to clear it. (When the request only sets one of the two, the
+        # other side is left untouched.)
+        if update_data.get("is_private") is True:
+            update_data["published"] = False
 
         next_name = update_data.get("name", current["name"])
         next_description = update_data.get("description", current.get("description") or "")
@@ -750,7 +757,12 @@ async def set_agent_private(
         if record is None:
             raise HTTPException(status_code=404, detail=f"Agent '{agent_id}' not found")
 
-        update = {"is_private": bool(body.is_private)}
+        update: dict[str, Any] = {"is_private": bool(body.is_private)}
+        # Mutual exclusion — see ``update_agent`` above. Moving an agent into
+        # the private square also drops the public ``published`` flag so we
+        # never end up with an agent that's "in both squares".
+        if update["is_private"]:
+            update["published"] = False
         if record.get("user_id") is None:
             updated = await store.update_builtin(agent_id, update)
         else: