refactor(profile): remove logout button

Profile page no longer shows logout button — logout is accessible via Sidebar dropdown menu only.

tauri-app/src/pages/Profile/Profile.tsx

@@ -104,10 +104,6 @@ export default function Profile() {
     }
   };
 
-  const handleLogout = () => {
-    navigate('logout');
-  };
-
   const displayName = user?.nickname || authUser?.nickname || '用户';
   const displayAvatar = user?.avatar || authUser?.avatar || '';
   const displayMobile = user?.mobile ? maskMobile(user.mobile) : '';
@@ -266,13 +262,6 @@ export default function Profile() {
         </div>
       </div>
 
-      {/* 退出登录 */}
-      <div className="profile-section-spaced">
-        <button className="profile-logout-btn" onClick={handleLogout}>
-          退出登录
-        </button>
-      </div>
-
       <RechargeModal
         open={showRechargeModal}
         onClose={() => setShowRechargeModal(false)}