feat(ios): P1-B — W7 UI wave: deep links, timeline, quick-reply, diff, projects, session switcher, thumbnails, lock-screen push

T-iOS-22: DeepLinkRouter (full-field whitelist, cold-start stash, route(from:) for push-tap reuse), 21 tests
T-iOS-24: TimelineSheet mirroring web render() order; disabled→empty-state; reuses AwayDigest onExpand
T-iOS-25: QuickReply chips (built-ins mirror quick-reply.ts via KeyByteMap; visible iff live gate && !readOnly)
T-iOS-27: read-only DiffScreen + App-layer DiffFetcher (RO no-Origin; APIClient fold-in noted for T-iOS-38 owner)
T-iOS-26: Projects list/detail — grouping byte-identical to web group keys (prefs-shared collapse state),
prefs-clobber defenses (no blind PUT on empty base; adopt server echo), claude\r bootstrap
T-iOS-23: UnreadLedger + TitleSanitizer (SessionCore, +15 tests), lastOutputAt decode, list-boundary re-sanitize
T-iOS-29: new-in-cwd (untrusted cwd, no bootstrap re-injection) + exited-session reopen; fixes stale-controller
SwiftTerm view bug via .id(controller.id)
T-iOS-28: offscreen SwiftTerm thumbnail pipeline (LRU 32, concurrency gate 2, 256KiB cap, grid clamp)
T-iOS-21: PushRegistrar (WEBTERM_GATE category: Allow=.authenticationRequired, no .foreground) +
NotificationActionHandler (whitelisted payload, token never persisted, bg-task-wrapped POST, 403 fallback)
CRITICAL fix (verify-found boot crash): @Sendable literals on UN completion closures — MainActor-inherited
closures trapped Swift 6 executor check on UN's background queue; boot re-verified (no new crash reports,
permission prompt reached, privacy shade correctly covering during system alert)
Verified: 261 pkg + 247 app + 10 integration tests green; 7/7 semantics checks; Owns audit clean

ios/App/WebTerm/ViewModels/ProjectDetailViewModel.swift

@@ -0,0 +1,76 @@
+import APIClient
+import Foundation
+import Observation
+import WireProtocol
+
+/// T-iOS-26 · 项目详情状态（`GET /projects/detail?path=` → phase 状态机，
+/// 与 DiffViewModel/TimelineViewModel 同一纪律）。
+///
+/// fetch 闭包注入 —— 生产由 `forHost` 包 `APIClient.projectDetail(path:)`
+/// （builder 百分号编码、400/404/500 `{error}` → 类型化错误均在 T-iOS-38
+/// 完成并已测）；测试注入 fake。本 VM 只归约用户可见的三种结局：
+/// - 成功 → `.loaded(ProjectDetail)`（sessions/worktrees/hasClaudeMd 透传）；
+/// - 400 → `.failed(.pathInvalid)`、404 → `.failed(.notFound)`、
+///   500/解码/传输 → `.failed(.unavailable)` —— 全部可经 `load()` 重试。
+@MainActor
+@Observable
+final class ProjectDetailViewModel {
+    /// 用户可见的失败三分类（文案映射在 ProjectDetailScreen）。
+    enum Failure: Equatable {
+        case pathInvalid
+        case notFound
+        case unavailable
+    }
+
+    enum Phase: Equatable {
+        case loading
+        case loaded(ProjectDetail)
+        case failed(Failure)
+    }
+
+    private(set) var phase: Phase = .loading
+    /// 详情/diff 的目标项目路径（来自列表行 —— 服务器数据；只透传给
+    /// builder，绝不本地拼 URL）。
+    let path: String
+
+    @ObservationIgnored
+    private let fetch: @Sendable () async throws -> ProjectDetail
+
+    init(path: String, fetch: @escaping @Sendable () async throws -> ProjectDetail) {
+        self.path = path
+        self.fetch = fetch
+    }
+
+    /// 生产装配缝（ProjectsViewModel.makeDetailViewModel 经此构造）。
+    static func forHost(
+        endpoint: HostEndpoint, http: any HTTPTransport, path: String
+    ) -> ProjectDetailViewModel {
+        let client = APIClient(endpoint: endpoint, http: http)
+        return ProjectDetailViewModel(path: path, fetch: {
+            try await client.projectDetail(path: path)
+        })
+    }
+
+    /// Fetch 并呈现。也是「重试」路径：`.failed` 后可再次调用。
+    func load() async {
+        phase = .loading
+        do {
+            phase = .loaded(try await fetch())
+        } catch let error as APIClientError {
+            phase = .failed(Self.failure(for: error))
+        } catch {
+            phase = .failed(.unavailable) // 传输层等其余错误：可重试兜底
+        }
+    }
+
+    private static func failure(for error: APIClientError) -> Failure {
+        switch error {
+        case .projectPathInvalid, .invalidRequest:
+            return .pathInvalid
+        case .projectNotFound:
+            return .notFound
+        default:
+            return .unavailable
+        }
+    }
+}