Migrate from iOS 17 Observation to iOS 16-compatible Combine architecture.

Lower deployment target to iOS 16, replace @Observable with ObservableObject, add navigation and UI compatibility shims, and include login smoke UI tests.

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

suixinkan/Features/WithdrawalAudit/ViewModels/WithdrawalAuditViewModel.swift

@@ -6,7 +6,7 @@
 //
 
 import Foundation
-import Observation
+import Combine
 
 /// 提现审核筛选项，按提现记录的状态文案聚合审核视角。
 enum WithdrawalAuditFilter: String, CaseIterable, Identifiable {
@@ -27,20 +27,19 @@ enum WithdrawalAuditFilter: String, CaseIterable, Identifiable {
 }
 
 @MainActor
-@Observable
 /// 提现审核 ViewModel，负责提现记录分页、状态筛选和失败状态清理。
-final class WithdrawalAuditViewModel {
-    var records: [WalletWithdrawRecord] = []
-    var selectedFilter: WithdrawalAuditFilter = .all
-    var isLoading = false
-    var isLoadingMore = false
-    var loadFailed = false
-    var loadFailureReason: String?
-    var errorMessage: String?
+final class WithdrawalAuditViewModel: ObservableObject {
+    @Published var records: [WalletWithdrawRecord] = []
+    @Published var selectedFilter: WithdrawalAuditFilter = .all
+    @Published var isLoading = false
+    @Published var isLoadingMore = false
+    @Published var loadFailed = false
+    @Published var loadFailureReason: String?
+    @Published var errorMessage: String?
 
     private let pageSize = 10
-    private var page = 1
-    private var total = 0
+    @Published private var page = 1
+    @Published private var total = 0
 
     /// 当前筛选下的提现记录。
     var filteredRecords: [WalletWithdrawRecord] {