新增任务模块，并接入首页任务管理路由

实现任务列表、详情与创建页面，对接 API，支持云端/本地附件，并添加单元测试。

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

suixinkan/Features/Tasks/ViewModels/TaskManagementViewModel.swift

@@ -0,0 +1,167 @@
+//
+//  TaskManagementViewModel.swift
+//  suixinkan
+//
+//  Created by Codex on 2026/6/23.
+//
+
+import Foundation
+import Observation
+
+/// 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 {
+    case all = 0
+    case unaccepted = 1
+    case accepted = 2
+    case completed = 3
+    case rejected = 4
+
+    var id: Int { rawValue }
+
+    /// 返回状态筛选在页面上的展示文案。
+    var title: String {
+        switch self {
+        case .all:
+            "全部"
+        case .unaccepted:
+            "待接收"
+        case .accepted:
+            "处理中"
+        case .completed:
+            "已完成"
+        case .rejected:
+            "已驳回"
+        }
+    }
+}
+
+/// 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?
+
+    private let pageSize = 10
+
+    /// 判断任务列表是否还有下一页。
+    var hasMore: Bool {
+        tasks.count < total
+    }
+
+    /// 首屏加载任务列表；无景区时清空旧数据且不请求接口。
+    func reload(api: any TaskServing, scenicId: Int?) async throws {
+        guard let scenicId else {
+            resetList()
+            errorMessage = "请先选择景区"
+            return
+        }
+
+        isLoading = true
+        errorMessage = nil
+        defer { isLoading = false }
+
+        do {
+            let payload = try await requestList(api: api, scenicId: scenicId, page: 1)
+            page = 1
+            tasks = payload.list
+            total = payload.total
+        } catch {
+            resetList()
+            errorMessage = error.localizedDescription
+            throw error
+        }
+    }
+
+    /// 加载下一页任务列表；最后一页或正在加载时不会重复请求。
+    func loadMore(api: any TaskServing, scenicId: Int?) async throws {
+        guard let scenicId, hasMore, !isLoadingMore else { return }
+        isLoadingMore = true
+        errorMessage = nil
+        defer { isLoadingMore = false }
+
+        let nextPage = page + 1
+        do {
+            let payload = try await requestList(api: api, scenicId: scenicId, page: nextPage)
+            page = nextPage
+            total = payload.total
+            tasks.append(contentsOf: payload.list)
+        } catch {
+            errorMessage = error.localizedDescription
+            throw error
+        }
+    }
+
+    /// 清空任务列表和分页状态。
+    func resetList() {
+        tasks = []
+        total = 0
+        page = 1
+        isLoading = false
+        isLoadingMore = false
+    }
+
+    /// 组装并发送任务列表请求。
+    private func requestList(api: any TaskServing, scenicId: Int, page: Int) async throws -> ListPayload<PhotographerTaskItem> {
+        try await api.taskList(
+            scenicId: scenicId,
+            page: page,
+            pageSize: pageSize,
+            taskStatus: selectedStatus.rawValue,
+            taskName: trimmedSearchText,
+            startTime: Self.requestDateString(from: startDate),
+            endTime: Self.requestDateString(from: endDate)
+        )
+    }
+
+    /// 搜索关键字去除空白后为空则不传给后端。
+    private var trimmedSearchText: String? {
+        let text = searchText.trimmingCharacters(in: .whitespacesAndNewlines)
+        return text.isEmpty ? nil : text
+    }
+
+    /// 日期请求格式化器。
+    private static let requestDateFormatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.calendar = Calendar(identifier: .gregorian)
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.dateFormat = "yyyy-MM-dd"
+        return formatter
+    }()
+
+    /// 将可选日期格式化成请求字符串。
+    private static func requestDateString(from date: Date?) -> String? {
+        guard let date else { return nil }
+        return requestDateFormatter.string(from: date)
+    }
+}
+
+/// 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?
+
+    /// 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 {
+        isLoading = true
+        errorMessage = nil
+        defer { isLoading = false }
+
+        do {
+            detail = try await api.taskDetail(id: taskId)
+        } catch {
+            errorMessage = error.localizedDescription
+        }
+    }
+}