feat(ios): comprehensive iPhone+iPad UX polish — refined-native design system

Freeze a shared design system (DesignSystem/{Tokens,Typography,StatusStyle,
Primitives}.swift): indigo #7C8CFF accent (root .tint), semantic status colors,
2-4-8-12-16-20-24 spacing + sm8/md12/lg16 radii scale, SF Mono tabular numbers,
reduce-motion-gated animations, haptics, reusable StatusBadge/TelemetryChip/Card/
SectionHeader/DSButtonStyle/ContinueLastBanner. Every changed view consumes tokens
— no hardcoded colors/spacing.

Applied across all surfaces (visual only — zero behavior/logic change, all suites
green): session list rows + status system (shape+color, not color-alone) +
telemetry chips + thumbnail placeholders; terminal gate card (≥44pt approve/reject)
+ keybar + reconnect + quick-reply + digest + SwiftTerm accent theme; pairing hero
+ warning tiers + Projects cards + Timeline/Diff; nav chrome + iPad split placeholder
+ privacy shade + motion. Chinese gate copy. UX finding fixed: timeline class colors
now via DS.Palette (+timelineTool/timelineUser tokens).

Design review 8.5/10. Verified: iPhone 16 290 + iPad Pro 11 290 tests green;
packages + integration green; consistency audit ~clean; zero changes under
ios/Packages, src/, public/.

ios/App/WebTerm/Wiring/SplitRootView.swift

@@ -10,12 +10,17 @@ import SwiftUI
 ///   split detail 无关，只换外层容器、内容零改（PLAN_IOS_IPAD §1）。
 /// - **选中态经 `AppCoordinator` 单一真值**：sidebar 触发面全部走
 ///   `selectSidebarItem` / `open`（同 stack 的既有路由），不新开会话生命周期。
+///   `coordinator.sidebarSelection` 提供二向绑定；行 highlight 需 sidebar List
+///   采纳 `selection:`（`SessionListScreen` 的 List，属列表组 Owns），见文末注。
 /// - **detail 终端仍带 `.id(controller.id)`**：换会话时新 controller → 新
 ///   SwiftTerm 视图（回放 ring buffer），identity 稳定复用 T-iOS-29 语义。
 /// - **隐私遮罩不在这里**：它在 `AdaptiveRootView` 的 ZStack 顶层，两分支共享，
 ///   故 detail 终端字节同样在 `scenePhase != .active` 时被遮（安全不变式）。
+/// - **视觉层**：横幅/占位/工具栏全部走冻结 `DS.*` token 与共享 Primitive，
+///   与 stack 分支像素级一致（继续横幅、项目入口都是同一组件）。
 struct SplitRootView: View {
     @Bindable var coordinator: AppCoordinator
+    @Environment(\.accessibilityReduceMotion) private var reduceMotion
 
     var body: some View {
         NavigationSplitView {
@@ -37,23 +42,19 @@ struct SplitRootView: View {
             onAddHost: { coordinator.presentAddHost() }
         )
         .safeAreaInset(edge: .bottom) { continueLastBanner }
-        .toolbar { projectsToolbarItem }
+        .animation(
+            DS.Motion.gated(DS.Motion.base, reduceMotion: reduceMotion),
+            value: coordinator.continueLastSessionId
+        )
+        .toolbar { ProjectsToolbarItem(coordinator: coordinator) }
     }
 
-    /// 与 `StackRootView.continueLastBanner` 同款「继续上次会话」（冷启动第 5 步）
-    /// —— 分栏 sidebar 也提供，iPad 用户不丢该入口（T-iPad-5 finding）。
+    /// 与 stack 底栏同款「继续上次会话」（冷启动第 5 步）—— 复用共享
+    /// `ContinueLastBanner`，iPad 用户不丢该入口（T-iPad-5 finding）。
     @ViewBuilder private var continueLastBanner: some View {
         if coordinator.continueLastSessionId != nil {
-            Button {
-                coordinator.openContinueLast()
-            } label: {
-                Label(RootCopy.continueLast, systemImage: "arrow.uturn.forward.circle.fill")
-                    .frame(maxWidth: .infinity)
-            }
-            .buttonStyle(.borderedProminent)
-            .padding(.horizontal, RootMetrics.bannerHorizontalPadding)
-            .padding(.vertical, RootMetrics.bannerVerticalPadding)
-            .background(.thinMaterial)
+            ContinueLastBanner { coordinator.openContinueLast() }
+                .transition(.move(edge: .bottom).combined(with: .opacity))
         }
     }
 
@@ -62,21 +63,6 @@ struct SplitRootView: View {
         request.sessionId.map(SidebarItem.session) ?? .newSession
     }
 
-    /// 与 `StackRootView.projectsToolbarItem` 同款（leading 位、同 disabled 条件、
-    /// 复用 `presentProjects`）—— iPad 上 Projects 本期仍走既有 sheet（大屏化留
-    /// 给 T-iPad-4）。
-    @ToolbarContentBuilder private var projectsToolbarItem: some ToolbarContent {
-        ToolbarItem(placement: .topBarLeading) {
-            Button {
-                coordinator.presentProjects()
-            } label: {
-                Label(RootCopy.projects, systemImage: "folder")
-            }
-            .disabled(coordinator.sessionList.activeHost == nil)
-            .accessibilityIdentifier("sessions.projectsButton")
-        }
-    }
-
     // MARK: - Detail（终端或占位）
 
     @ViewBuilder private var detail: some View {
@@ -91,19 +77,27 @@ struct SplitRootView: View {
             }
         } else {
             placeholder
+                .transition(.opacity)
         }
     }
 
+    /// 空 detail 占位 —— accent 图标 + 邀约式文案（DS 方向：ContentUnavailableView
+    /// + 好符号 + 友好中文）。图标着 accent 靛紫，与全 App 强调色呼应。
     private var placeholder: some View {
         ContentUnavailableView {
-            Label(SplitCopy.placeholderTitle, systemImage: "sidebar.left")
+            Label {
+                Text(SplitCopy.placeholderTitle)
+            } icon: {
+                Image(systemName: "terminal")
+                    .foregroundStyle(DS.Palette.accent)
+            }
         } description: {
             Text(SplitCopy.placeholderHint)
         }
     }
 }
 
-/// split 专属用户可见文案（「项目」标签复用 `RootCopy.projects`，DRY）。
+/// split 专属用户可见文案（「项目」/「继续」标签复用 `RootCopy`，DRY）。
 private enum SplitCopy {
     static let placeholderTitle = "选择或新建会话"
     static let placeholderHint = "从左侧选择一个运行中的会话，或新建一个开始工作。"