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/ScenicPermission/Views/ScenicApplicationView.swift

@@ -10,9 +10,9 @@ import SwiftUI
 
 /// 景区申请页面，支持新增景区入驻资料、图片上传和审核状态回填。
 struct ScenicApplicationView: View {
-    @Environment(ScenicPermissionAPI.self) private var scenicPermissionAPI
-    @Environment(OSSUploadService.self) private var ossUploadService
-    @State private var viewModel = ScenicApplicationViewModel()
+    @Environment(\.scenicPermissionAPI) private var scenicPermissionAPI
+    @Environment(\.ossUploadService) private var ossUploadService
+    @StateObject private var viewModel = ScenicApplicationViewModel()
     @State private var pickedImageItems: [PhotosPickerItem] = []
     @State private var activeLocationPicker: ScenicLocationPicker?
 
@@ -21,7 +21,7 @@ struct ScenicApplicationView: View {
             ScrollView {
                 VStack(spacing: AppMetrics.Spacing.medium) {
                     if viewModel.loadFailed {
-                        ContentUnavailableView(
+                        AppContentUnavailableView(
                             "景区申请初始化失败",
                             systemImage: "exclamationmark.triangle",
                             description: Text(viewModel.loadFailureReason ?? "请检查网络后重试")
@@ -48,7 +48,7 @@ struct ScenicApplicationView: View {
         .task {
             await viewModel.loadInitial(api: scenicPermissionAPI)
         }
-        .onChange(of: pickedImageItems) { _, items in
+        .onChange(of: pickedImageItems) { items in
             guard !items.isEmpty else { return }
             Task {
                 await importPickedImages(items)
@@ -111,7 +111,7 @@ struct ScenicApplicationView: View {
             locationSection
             coopTypeSection
             inputField("备注信息 (\(viewModel.remark.count)/50)", text: $viewModel.remark, axis: .vertical, disabled: viewModel.isReadOnly)
-                .onChange(of: viewModel.remark) { _, value in
+                .onChange(of: viewModel.remark) { value in
                     if value.count > 50 {
                         viewModel.remark = String(value.prefix(50))
                     }