refactor: 将退出登录功能从顶部导航栏移至设置面板

frontend/src/App.tsx

@@ -234,12 +234,6 @@ function AppContent() {
           <span className="header__subtitle">{tr("app.title")}</span>
         </div>
         <div className="header__right">
-          <div className="header__user">
-            <span className="header__username">{user?.username}</span>
-            <button className="header__logout-btn" onClick={logout}>
-              {tr("auth.logout")}
-            </button>
-          </div>
           <span className={`badge badge--${connectionStatus}`}>
             {isConnected ? tr("status.connected") : connectionStatus === "connecting" ? tr("status.connecting") : tr("status.disconnected")}
           </span>
@@ -273,8 +267,10 @@ function AppContent() {
         <ConfigPanel
           config={config}
           theme={theme}
+          username={user?.username}
           onUpdate={updateConfig}
           onThemeChange={handleThemeChange}
+          onLogout={logout}
           onClose={() => setShowConfig(false)}
         />
       )}