feat(models): 模型自动下载(我的·模型管理) + 断点续传 + 旁路导入

实现 spec(2026-05-29-model-download-design)的模型分发功能:
- ModelManifest: 硬编码功能文件清单 + base URL https://file.myv0.com/
- FileDownloader: URLSessionDataDelegate 分块写盘,HTTP Range 断点续传 + 大小校验
  (根因修复:URL.resourceValues 会缓存文件大小,续传时先读 offset 再读 finalSize
   会拿到下载前的陈旧值导致校验误判;改用 FileManager.attributesOfItem)
- ModelDownloadService: @MainActor @Observable 编排逐文件下载,聚合进度/速度,
  支持下载全部/暂停/重试,以及旁路文件导入
- ModelStore: 新增 fileURL/localBytes/isComplete(可注入清单)/importModel(补 VL)
- ModelManagementView: 分模型卡片(状态/进度/速度) + 下载全部/暂停
  + NWPathMonitor 蜂窝提示 + 从文件导入(离线兜底)
- MeView: 模型管理卡改 NavigationLink + 动态状态(已就绪/下载中/N就绪)

测试(Swift Testing): Manifest 清单/字节数、Store 路径/校验/导入、
DownloadState、FileDownloader(URLProtocol mock:下载/Range续传/大小校验)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

康康/Features/Me/MeView.swift

@@ -7,6 +7,8 @@ struct MeView: View {
     @Query private var reminders: [MetricReminder]
     @Query private var customMetrics: [CustomMonitorMetric]
 
+    @State private var downloadService = ModelDownloadService.shared
+
     private var profile: UserProfile? { profiles.first }
     private var enabledReminderCount: Int { reminders.filter(\.enabled).count }
 
@@ -17,9 +19,7 @@ struct MeView: View {
                     profileCard
                     remindersCard
                     customMetricsCard
-                    settingsCard(title: "模型管理",
-                                 detail: "未配置",
-                                 icon: "cpu")
+                    modelManagementCard
                     settingsCard(title: "Face ID 启动锁",
                                  detail: "关闭",
                                  icon: "faceid")
@@ -42,6 +42,7 @@ struct MeView: View {
                 if profiles.isEmpty {
                     _ = UserProfileStore.loadOrCreate(in: ctx)
                 }
+                downloadService.refreshStates()
             }
         }
     }
@@ -161,6 +162,23 @@ struct MeView: View {
         return "\(customMetrics.count) 项"
     }
 
+    private var modelManagementCard: some View {
+        NavigationLink {
+            ModelManagementView()
+        } label: {
+            settingsCard(title: "模型管理", detail: modelDetail, icon: "cpu")
+        }
+        .buttonStyle(.plain)
+    }
+
+    private var modelDetail: String {
+        let states = downloadService.states
+        if ModelKind.allCases.allSatisfy({ states[$0]?.phase == .ready }) { return "已就绪" }
+        if downloadService.isAnyDownloading { return "下载中…" }
+        let readyCount = ModelKind.allCases.filter { states[$0]?.phase == .ready }.count
+        return readyCount == 0 ? "未下载" : "\(readyCount)/\(ModelKind.allCases.count) 就绪"
+    }
+
     private func settingsCard(title: String, detail: String, icon: String) -> some View {
         HStack(spacing: 12) {
             ZStack {

康康/Features/Me/ModelManagementView.swift

@@ -0,0 +1,226 @@
+import SwiftUI
+import Network
+import UniformTypeIdentifiers
+
+/// 「我的 · 模型管理」页:分模型卡片显示下载状态/进度,支持下载全部/暂停 + 旁路文件导入。
+/// 只观察 ModelDownloadService 的状态,不直接碰 URLSession(§3.1)。
+struct ModelManagementView: View {
+    @State private var service = ModelDownloadService.shared
+    @State private var isCellular = false
+    @State private var showCellularConfirm = false
+    @State private var showImporter = false
+    @State private var importError: String?
+
+    private let monitor = NWPathMonitor()
+    private let monitorQueue = DispatchQueue(label: "kk.netmonitor")
+
+    private var allReady: Bool {
+        ModelKind.allCases.allSatisfy { service.states[$0]?.phase == .ready }
+    }
+
+    var body: some View {
+        ScrollView {
+            VStack(spacing: 14) {
+                ForEach(ModelKind.allCases, id: \.self) { kind in
+                    modelCard(kind)
+                }
+
+                actionButtons
+                    .padding(.top, 4)
+
+                if let importError {
+                    Text(importError)
+                        .font(.system(size: 12))
+                        .foregroundStyle(Tj.Palette.brick)
+                        .frame(maxWidth: .infinity, alignment: .leading)
+                }
+
+                footer
+                    .padding(.top, 8)
+            }
+            .padding(.horizontal, 16)
+            .padding(.vertical, 18)
+        }
+        .background(Tj.Palette.sand.ignoresSafeArea())
+        .navigationTitle("模型管理")
+        .navigationBarTitleDisplayMode(.inline)
+        .onAppear {
+            service.refreshStates()
+            monitor.pathUpdateHandler = { path in
+                let cellular = path.status == .satisfied && path.usesInterfaceType(.cellular)
+                Task { @MainActor in isCellular = cellular }
+            }
+            monitor.start(queue: monitorQueue)
+        }
+        .onDisappear { monitor.cancel() }
+        .fileImporter(isPresented: $showImporter,
+                      allowedContentTypes: [.folder]) { handleImport($0) }
+        .alert("使用蜂窝网络下载?", isPresented: $showCellularConfirm) {
+            Button("取消", role: .cancel) {}
+            Button("继续下载") { service.downloadAll() }
+        } message: {
+            Text("模型约 \(formatBytes(totalAllBytes)),建议在 Wi-Fi 下下载。")
+        }
+    }
+
+    // MARK: - 模型卡片
+
+    private func modelCard(_ kind: ModelKind) -> some View {
+        let state = service.states[kind]
+            ?? DownloadState(phase: .idle, receivedBytes: 0,
+                             totalBytes: ModelManifest.totalBytes(for: kind), bytesPerSecond: 0)
+        return VStack(alignment: .leading, spacing: 10) {
+            HStack(alignment: .top) {
+                VStack(alignment: .leading, spacing: 3) {
+                    Text(kind.displayName)
+                        .font(.system(size: 15, weight: .semibold))
+                        .foregroundStyle(Tj.Palette.text)
+                    Text(subtitle(kind))
+                        .font(.system(size: 12))
+                        .foregroundStyle(Tj.Palette.text3)
+                }
+                Spacer()
+                statusBadge(state.phase)
+            }
+
+            if state.phase == .downloading {
+                ProgressView(value: min(max(state.fraction, 0), 1))
+                    .tint(Tj.Palette.ink)
+                HStack {
+                    Text("\(Int(state.fraction * 100))%")
+                    Spacer()
+                    Text(speedText(state))
+                }
+                .font(.system(size: 11, design: .monospaced))
+                .foregroundStyle(Tj.Palette.text3)
+            } else {
+                HStack {
+                    Text(formatBytes(ModelManifest.totalBytes(for: kind)))
+                        .font(.system(size: 11, design: .monospaced))
+                        .foregroundStyle(Tj.Palette.text3)
+                    Spacer()
+                    if case .failed(let message) = state.phase {
+                        Text(message)
+                            .font(.system(size: 11))
+                            .foregroundStyle(Tj.Palette.brick)
+                            .lineLimit(1)
+                    }
+                }
+            }
+        }
+        .padding(14)
+        .frame(maxWidth: .infinity, alignment: .leading)
+        .tjCard()
+        .contentShape(Rectangle())
+        .onTapGesture {
+            if case .failed = state.phase { service.download(kind) }
+        }
+    }
+
+    private func statusBadge(_ phase: DownloadPhase) -> some View {
+        switch phase {
+        case .idle:        return TjBadge(text: "待下载", style: .neutral)
+        case .downloading: return TjBadge(text: "下载中", style: .amber)
+        case .verifying:   return TjBadge(text: "校验中", style: .amber)
+        case .ready:       return TjBadge(text: "已就绪", style: .leaf)
+        case .failed:      return TjBadge(text: "失败 · 重试", style: .brick)
+        }
+    }
+
+    // MARK: - 动作按钮
+
+    @ViewBuilder
+    private var actionButtons: some View {
+        if service.isAnyDownloading {
+            Button {
+                for kind in ModelKind.allCases { service.cancel(kind) }
+            } label: {
+                Text("暂停下载").frame(maxWidth: .infinity)
+            }
+            .buttonStyle(TjGhostButton())
+        } else if allReady {
+            HStack(spacing: 6) {
+                Image(systemName: "checkmark.seal.fill")
+                Text("两个模型都已就绪")
+            }
+            .font(.system(size: 13, weight: .semibold))
+            .foregroundStyle(Tj.Palette.leaf)
+            .frame(maxWidth: .infinity)
+            .padding(.vertical, 6)
+        } else {
+            Button {
+                if isCellular { showCellularConfirm = true } else { service.downloadAll() }
+            } label: {
+                Text("下载全部模型 · \(formatBytes(totalAllBytes))")
+                    .frame(maxWidth: .infinity)
+            }
+            .buttonStyle(TjPrimaryButton())
+        }
+
+        Button {
+            importError = nil
+            showImporter = true
+        } label: {
+            Text("从文件导入(离线)").frame(maxWidth: .infinity)
+        }
+        .buttonStyle(TjGhostButton())
+    }
+
+    private var footer: some View {
+        VStack(spacing: 8) {
+            TjLockChip()
+            Text("100% 本地推理 · 模型仅需下载一次")
+                .font(.system(size: 11))
+                .foregroundStyle(Tj.Palette.text3)
+        }
+        .frame(maxWidth: .infinity)
+    }
+
+    // MARK: - 旁路导入
+
+    private func handleImport(_ result: Result<URL, Error>) {
+        do {
+            let folder = try result.get()
+            let scoped = folder.startAccessingSecurityScopedResource()
+            defer { if scoped { folder.stopAccessingSecurityScopedResource() } }
+
+            let name = folder.lastPathComponent
+            guard let kind = ModelKind.allCases.first(where: { $0.rawValue == name }) else {
+                importError = "请选择名为 Qwen3-1.7B-4bit 或 Qwen2.5-VL-3B-Instruct-4bit 的文件夹"
+                return
+            }
+            try service.importModel(kind, from: folder)
+            importError = nil
+        } catch {
+            importError = "导入失败:\(error.localizedDescription)"
+        }
+    }
+
+    // MARK: - 辅助
+
+    private var totalAllBytes: Int {
+        ModelKind.allCases.reduce(0) { $0 + ModelManifest.totalBytes(for: $1) }
+    }
+
+    private func subtitle(_ kind: ModelKind) -> String {
+        switch kind {
+        case .llm: return "文本解读 · 趋势 / 问答"
+        case .vl:  return "拍照识别报告 → 结构化指标"
+        }
+    }
+
+    private func formatBytes(_ bytes: Int) -> String {
+        ByteCountFormatter.string(fromByteCount: Int64(bytes), countStyle: .file)
+    }
+
+    private func speedText(_ state: DownloadState) -> String {
+        guard state.bytesPerSecond > 0 else { return "—" }
+        return formatBytes(Int(state.bytesPerSecond)) + "/s"
+    }
+}
+
+#Preview {
+    NavigationStack {
+        ModelManagementView()
+    }
+}