移除 MJRefresh 依赖，恢复 SwiftUI 系统下拉刷新。

同时收紧各 ViewModel 内部 isLoading 可见性，避免不必要的视图刷新。

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan/Features/Profile/ViewModels/ProfileViewModel.swift

@@ -13,7 +13,7 @@ import Combine
 final class ProfileViewModel: ObservableObject {
     @Published var userInfo: UserInfoResponse?
     @Published var realNameInfo: RealNameInfo?
-    @Published var isLoading = false
+    private var isLoading = false
     @Published var isSaving = false
     @Published var isEditingProfile = false
     @Published var editingNickname = ""