从 iOS 17 Observation 迁移至 iOS 16 兼容的 Combine 架构

将最低部署版本降至 iOS 16，以 ObservableObject 替换 @Observable，新增导航与 UI 兼容层，并补充登录冒烟 UI 测试。

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

suixinkan/Features/Main/Views/MainTabsView.swift

@@ -32,11 +32,9 @@ struct MainTabsView: View {
 
 /// 系统 TabView 外壳，保留原生 TabBar 行为以便后续切换回系统实现。
 private struct SystemMainTabsView: View {
-    @Environment(AppRouter.self) private var appRouter
+    @EnvironmentObject private var appRouter: AppRouter
 
     var body: some View {
-        @Bindable var appRouter = appRouter
-
         TabView(selection: $appRouter.selectedTab) {
             ForEach(AppTab.allCases) { tab in
                 TabNavigationStackHost(tab: tab)
@@ -49,12 +47,12 @@ private struct SystemMainTabsView: View {
 
 /// 自定义 TabBar 外壳，复用每个 Tab 独立 NavigationStack 并保留已访问页面状态。
 private struct CustomMainTabsView: View {
-    @Environment(AccountContext.self) private var accountContext
-    @Environment(AppRouter.self) private var appRouter
-    @Environment(OrdersAPI.self) private var ordersAPI
-    @Environment(ToastCenter.self) private var toastCenter
+    @EnvironmentObject private var accountContext: AccountContext
+    @EnvironmentObject private var appRouter: AppRouter
+    @Environment(\.ordersAPI) private var ordersAPI
+    @EnvironmentObject private var toastCenter: ToastCenter
 
-    @State private var badgeViewModel = MainTabBadgeViewModel()
+    @StateObject private var badgeViewModel = MainTabBadgeViewModel()
     @State private var showScanner = false
     @State private var loadedTabs: Set<AppTab> = [.home]
 
@@ -66,8 +64,6 @@ private struct CustomMainTabsView: View {
     }
 
     var body: some View {
-        @Bindable var appRouter = appRouter
-
         ZStack {
             ForEach(AppTab.allCases) { tab in
                 PreservedTabPage(
@@ -102,15 +98,15 @@ private struct CustomMainTabsView: View {
             loadedTabs.insert(appRouter.selectedTab)
             await refreshOrderBadge()
         }
-        .onChange(of: appRouter.selectedTab) { _, selectedTab in
+        .onChange(of: appRouter.selectedTab) { selectedTab in
             loadedTabs.insert(selectedTab)
             guard selectedTab == .orders else { return }
             Task { await refreshOrderBadge() }
         }
-        .onChange(of: accountContext.currentScenic?.id) { _, _ in
+        .onChange(of: accountContext.currentScenic?.id) { _ in
             Task { await refreshOrderBadge() }
         }
-        .onChange(of: accountContext.currentStore?.id) { _, _ in
+        .onChange(of: accountContext.currentStore?.id) { _ in
             Task { await refreshOrderBadge() }
         }
     }
@@ -127,7 +123,7 @@ private struct CustomMainTabsView: View {
 
 /// 自定义 TabBar 模式下的单个 Tab 导航栈，TabBar 只属于根页面内容。
 private struct CustomTabNavigationStackHost: View {
-    @Environment(AppRouter.self) private var appRouter
+    @EnvironmentObject private var appRouter: AppRouter
 
     let tab: AppTab
     @Binding var selectedTab: AppTab
@@ -153,13 +149,13 @@ private struct CustomTabNavigationStackHost: View {
                     .toolbar(route.hidesTabBarWhenPushed ? .hidden : .visible, for: .tabBar)
             }
         }
-        .environment(appRouter.router(for: tab))
+        .environmentObject(appRouter.router(for: tab))
     }
 }
 
 /// 单个 Tab 对应的导航栈，供系统和自定义 TabBar 外壳共同复用。
 private struct TabNavigationStackHost: View {
-    @Environment(AppRouter.self) private var appRouter
+    @EnvironmentObject private var appRouter: AppRouter
 
     let tab: AppTab
 
@@ -172,7 +168,7 @@ private struct TabNavigationStackHost: View {
                         .toolbar(route.hidesTabBarWhenPushed ? .hidden : .visible, for: .tabBar)
                 }
         }
-        .environment(appRouter.router(for: tab))
+        .environmentObject(appRouter.router(for: tab))
     }
 }
 
@@ -197,8 +193,8 @@ private struct PreservedTabPage<Content: View>: View {
 
 #Preview {
     MainTabsView()
-        .environment(AppRouter())
-        .environment(AccountContext())
-        .environment(OrdersAPI(client: APIClient()))
-        .environment(ToastCenter())
+        .environmentObject(AppRouter())
+        .environmentObject(AccountContext())
+        .environment(\.ordersAPI, OrdersAPI(client: APIClient()))
+        .environmentObject(ToastCenter())
 }

suixinkan/Features/Main/Views/PlaceholderRootViews.swift

@@ -37,7 +37,7 @@ struct ProfileRootView: View {
 
 /// 通用 Tab 占位视图，用于未迁移模块的临时入口。
 private struct PlaceholderTabRootView: View {
-    @Environment(RouterPath.self) private var router
+    @EnvironmentObject private var router: RouterPath
 
     let title: String
     let systemImage: String