feat: 重构用户认证逻辑，添加导航重定向功能，更新相关组件和路由

src/views/user-settings/username.vue

@@ -4,7 +4,8 @@ import { arrowBackOutline } from "ionicons/icons";
 import { safeClient } from "@/api";
 import { authClient } from "@/auth";
 
-const { user } = useAuth();
+const userStore = useUserStore();
+const { user } = storeToRefs(userStore);
 const username = ref(user.value?.username || "");
 const { updateProfile } = useUserStore();