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/OperatingArea/API/OperatingAreaAPI.swift

@@ -6,7 +6,7 @@
 //
 
 import Foundation
-import Observation
+import Combine
 
 /// 运营区域服务协议，定义店铺和景区管理员两类围栏数据接口。
 @MainActor
@@ -16,10 +16,9 @@ protocol OperatingAreaServing {
 }
 
 @MainActor
-@Observable
 /// 运营区域 API，封装运营区域只读围栏接口。
 final class OperatingAreaAPI {
-    @ObservationIgnored private let client: APIClient
+    private let client: APIClient
 
     /// 初始化运营区域 API，并注入共享网络客户端。
     init(client: APIClient) {

suixinkan/Features/OperatingArea/ViewModels/OperatingAreaViewModel.swift

@@ -6,18 +6,17 @@
 //
 
 import Foundation
-import Observation
+import Combine
 
 @MainActor
-@Observable
 /// 运营区域 ViewModel，负责角色分流、围栏加载、解析和错误状态管理。
-final class OperatingAreaViewModel {
-    private(set) var mode: OperatingAreaEntryMode?
-    private(set) var loading = false
-    private(set) var items: [OperatingAreaItem] = []
-    private(set) var fenceRings: [OperatingFenceRing] = []
-    private(set) var blockReason: OperatingAreaBlockReason?
-    private(set) var errorMessage: String?
+final class OperatingAreaViewModel: ObservableObject {
+    @Published private(set) var mode: OperatingAreaEntryMode?
+    @Published private(set) var loading = false
+    @Published private(set) var items: [OperatingAreaItem] = []
+    @Published private(set) var fenceRings: [OperatingFenceRing] = []
+    @Published private(set) var blockReason: OperatingAreaBlockReason?
+    @Published private(set) var errorMessage: String?
 
     /// 按当前账号和角色刷新运营区域。
     func reload(

suixinkan/Features/OperatingArea/Views/OperatingAreaViews.swift

@@ -14,13 +14,13 @@ import MAMapKit
 
 /// 运营区域首页，按当前角色展示店铺或景区运营围栏。
 struct OperatingAreaView: View {
-    @Environment(AccountContext.self) private var accountContext
-    @Environment(PermissionContext.self) private var permissionContext
-    @Environment(OperatingAreaAPI.self) private var operatingAreaAPI
-    @Environment(ToastCenter.self) private var toastCenter
+    @EnvironmentObject private var accountContext: AccountContext
+    @EnvironmentObject private var permissionContext: PermissionContext
+    @Environment(\.operatingAreaAPI) private var operatingAreaAPI
+    @EnvironmentObject private var toastCenter: ToastCenter
     @Environment(\.globalLoading) private var globalLoading
 
-    @State private var viewModel = OperatingAreaViewModel()
+    @StateObject private var viewModel = OperatingAreaViewModel()
 
     var body: some View {
         ScrollView {
@@ -87,7 +87,7 @@ struct OperatingAreaView: View {
             }
 
             if let reason = viewModel.blockReason {
-                ContentUnavailableView(reason.message, systemImage: "mappin.slash")
+                AppContentUnavailableView(reason.message, systemImage: "mappin.slash")
                     .frame(maxWidth: .infinity, minHeight: 260)
                     .background(Color(hex: 0xF8FAFC), in: RoundedRectangle(cornerRadius: 8))
                     .overlay(alignment: .bottom) {