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/Tasks/ViewModels/TaskManagementViewModel.swift

@@ -6,7 +6,7 @@
 //
 
 import Foundation
-import Observation
+import Combine
 
 /// 任务状态筛选实体，表示任务管理页支持的任务状态。
 enum TaskStatusFilter: Int, CaseIterable, Identifiable {
@@ -37,18 +37,17 @@ enum TaskStatusFilter: Int, CaseIterable, Identifiable {
 
 /// 任务管理 ViewModel，负责任务列表、筛选、分页和错误状态。
 @MainActor
-@Observable
-final class TaskManagementViewModel {
-    var isLoading = false
-    var isLoadingMore = false
-    var tasks: [PhotographerTaskItem] = []
-    var total = 0
-    var page = 1
-    var selectedStatus: TaskStatusFilter = .all
-    var searchText = ""
-    var startDate: Date?
-    var endDate: Date?
-    var errorMessage: String?
+final class TaskManagementViewModel: ObservableObject {
+    @Published var isLoading = false
+    @Published var isLoadingMore = false
+    @Published var tasks: [PhotographerTaskItem] = []
+    @Published var total = 0
+    @Published var page = 1
+    @Published var selectedStatus: TaskStatusFilter = .all
+    @Published var searchText = ""
+    @Published var startDate: Date?
+    @Published var endDate: Date?
+    @Published var errorMessage: String?
 
     private let pageSize = 10
 
@@ -146,11 +145,10 @@ final class TaskManagementViewModel {
 
 /// 任务详情 ViewModel，负责详情加载和列表摘要兜底展示。
 @MainActor
-@Observable
-final class TaskDetailViewModel {
-    var isLoading = false
-    var detail: TaskDetailResponse?
-    var errorMessage: String?
+final class TaskDetailViewModel: ObservableObject {
+    @Published var isLoading = false
+    @Published var detail: TaskDetailResponse?
+    @Published var errorMessage: String?
 
     /// 加载任务详情；接口失败时保留外部传入的列表摘要。
     func load(api: any TaskServing, taskId: Int) async {