feat(ipad): W1-W3 — adaptive split-view layout + finding fixes

T-iPad-2: AdaptiveRootView/LayoutPolicy (sole size-class decision), SplitRootView
(NavigationSplitView sidebar+detail), StackRootView (iPhone path verbatim, zero
regression); privacy shade hoisted to shared ZStack top for both branches
T-iPad-3: KeyBarVisibility predicate (hide when hardware keyboard present),
pointer context menu (copy/new-in-cwd/kill, all via existing channels)
T-iPad-4: Projects multi-column grid on iPad (idiom-gated), adaptive sheet detents
T-iPad-5 findings (4/4 fixed): kill onKillSession thread-through +
AppCoordinator.killCurrentSession; split route-gated to .sessions (iPad first-run
pairing); continue-last banner in split sidebar; iPad XCUITest deferred (covered
by SidebarSelectionTests)
Verified: iPhone 16 277 + iPad Pro 11 278 tests green; packages 261 + integration 10;
zero changes under ios/Packages, src/, public/

ios/App/WebTerm/Screens/TerminalScreen.swift

@@ -1,3 +1,4 @@
+import GameController
 import SessionCore
 import SwiftTerm
 import SwiftUI
@@ -25,6 +26,16 @@ struct TerminalScreen: View {
     /// `AppCoordinator.openNewSessionInCurrentCwd`）。nil = 两处入口都隐藏
     /// （预览/无 coordinator 的测试环境）。
     var onNewSessionInCwd: (@MainActor () -> Void)? = nil
+    /// T-iPad-3 · 上下文菜单「结束会话」动作 —— wiring 侧路由到
+    /// `APIClient.killSession`（带 Origin 的 G 端点）。nil = 无 kill 通道时
+    /// 菜单不呈现该项（预览/未布线环境）。
+    var onKillSession: (@MainActor () -> Void)? = nil
+
+    /// T-iPad-3 · 硬件键盘在场标记（`GCKeyboard.coalesced != nil`），随
+    /// 连接/断开通知更新，驱动 `KeyBarVisibility` 的自动默认。
+    @State private var hasHardwareKeyboard = GCKeyboard.coalesced != nil
+    /// T-iPad-3 · 用户对 KeyBar 的显式覆盖：nil = 跟随自动默认。
+    @State private var keyBarUserOverride: Bool?
 
     private enum Metrics {
         static let bannerHorizontalPadding: CGFloat = 12
@@ -33,10 +44,25 @@ struct TerminalScreen: View {
 
     private enum Copy {
         static let newSessionInCwd = "在当前目录开新会话"
+        static let showKeyBar = "显示快捷键栏"
+        static let hideKeyBar = "隐藏快捷键栏"
+    }
+
+    /// KeyBar 是否可见 —— 唯一判据经 `KeyBarVisibility` 纯谓词。
+    private var isKeyBarVisible: Bool {
+        KeyBarVisibility.isVisible(
+            hardwareKeyboardPresent: hasHardwareKeyboard,
+            userOverride: keyBarUserOverride
+        )
     }
 
     var body: some View {
-        TerminalHostView(viewModel: viewModel)
+        TerminalHostView(
+            viewModel: viewModel,
+            keyBarVisible: isKeyBarVisible,
+            onNewSessionInCwd: onNewSessionInCwd,
+            onKillSession: onKillSession
+        )
             .ignoresSafeArea(.container, edges: .bottom)
             .overlay(alignment: .top) {
                 if let model = viewModel.bannerModel {
@@ -47,10 +73,39 @@ struct TerminalScreen: View {
                 }
             }
             .animation(.default, value: viewModel.bannerModel)
-            .toolbar { newSessionToolbarItem }
+            .toolbar {
+                newSessionToolbarItem
+                keyBarToggleToolbarItem
+            }
+            .onReceive(NotificationCenter.default.publisher(for: .GCKeyboardDidConnect)) { _ in
+                hasHardwareKeyboard = true
+            }
+            .onReceive(NotificationCenter.default.publisher(for: .GCKeyboardDidDisconnect)) { _ in
+                hasHardwareKeyboard = GCKeyboard.coalesced != nil
+            }
             .onAppear { viewModel.start() }
     }
 
+    /// T-iPad-3 · KeyBar 手动切换。仅在硬件键盘在场时出现 —— 无硬件键盘的
+    /// iPhone 默认工具栏因此逐屏不变（零回归）；有硬件键盘时（自动隐藏后）
+    /// 用户可一键取回/再隐。切换即写显式覆盖，压过自动默认。
+    @ToolbarContentBuilder private var keyBarToggleToolbarItem: some ToolbarContent {
+        if hasHardwareKeyboard {
+            ToolbarItem(placement: .topBarTrailing) {
+                Button {
+                    keyBarUserOverride = !isKeyBarVisible
+                } label: {
+                    Label(
+                        isKeyBarVisible ? Copy.hideKeyBar : Copy.showKeyBar,
+                        systemImage: isKeyBarVisible
+                            ? "keyboard.chevron.compact.down" : "keyboard"
+                    )
+                }
+                .accessibilityIdentifier("terminal.keyBarToggleButton")
+            }
+        }
+    }
+
     /// Mirrors web `tabs.ts newTab()` (M6): the + affordance opens a fresh
     /// session in the active session's cwd, if known.
     @ToolbarContentBuilder private var newSessionToolbarItem: some ToolbarContent {
@@ -74,6 +129,11 @@ struct TerminalScreen: View {
 /// `KeyCommandTerminalView` subclass. Both route through the ViewModel.
 private struct TerminalHostView: UIViewRepresentable {
     let viewModel: TerminalViewModel
+    /// T-iPad-3 · KeyBar (`inputAccessoryView`) 可见性，由 `KeyBarVisibility`
+    /// 谓词在 SwiftUI 侧算出；`updateUIView` 仅在变化时增量应用。
+    let keyBarVisible: Bool
+    var onNewSessionInCwd: (@MainActor () -> Void)? = nil
+    var onKillSession: (@MainActor () -> Void)? = nil
 
     func makeCoordinator() -> Coordinator {
         Coordinator(viewModel: viewModel)
@@ -88,7 +148,14 @@ private struct TerminalHostView: UIViewRepresentable {
 
         let keyBar = KeyBarView()
         keyBar.onKey = { key in viewModel.send(key: key) }
-        terminal.inputAccessoryView = keyBar
+        terminal.installKeyBar(keyBar, visible: keyBarVisible)
+
+        // T-iPad-3 · 指针右键/长按上下文菜单（仅 iPad 安装 —— iPhone 长按保持
+        // SwiftTerm 选区手势）。动作复用既有通道，无新增网络路径。
+        terminal.installPointerContextMenuIfSupported(
+            onNewInCwd: onNewSessionInCwd,
+            onKill: onKillSession
+        )
 
         // Output sink: buffered replay flushes now, live bytes follow.
         // @MainActor-typed closure — feeding off the main actor cannot compile.
@@ -100,7 +167,10 @@ private struct TerminalHostView: UIViewRepresentable {
 
     func updateUIView(_ uiView: KeyCommandTerminalView, context: Context) {
         // State-driven UI lives in SwiftUI (banner overlay); the terminal view
-        // itself is driven by the sink/delegate, nothing to push here.
+        // itself is driven by the sink/delegate. The only push is the KeyBar
+        // visibility (hardware-keyboard aware / user toggle) — a no-op unless it
+        // actually changed, so iPhone (always-visible) never reloads input views.
+        uiView.setKeyBarVisible(keyBarVisible)
     }
 
     /// SwiftTerm's delegate is a pre-concurrency protocol; the conformance is
@@ -164,6 +234,14 @@ final class KeyCommandTerminalView: TerminalView {
     /// Chord outlet; the screen routes it to `TerminalViewModel.send(key:)`.
     var onKeyCommand: (@MainActor (KeyByteMap.Key) -> Void)?
 
+    /// Retained KeyBar so visibility can toggle it in/out of `inputAccessoryView`
+    /// (T-iPad-3). The last-applied value avoids reloading input views when the
+    /// visibility did not change (iPhone stays byte-identical).
+    private var keyBar: KeyBarView?
+    private var appliedKeyBarVisible = true
+    /// Retained so the interaction's delegate outlives menu presentation.
+    private var contextMenuDelegate: TerminalContextMenuInteractionDelegate?
+
     override var keyCommands: [UIKeyCommand]? {
         (super.keyCommands ?? [])
             + HardwareKeyCommands.build(action: #selector(runHardwareKeyCommand(_:)))
@@ -173,4 +251,64 @@ final class KeyCommandTerminalView: TerminalView {
         guard let key = HardwareKeyCommands.key(matching: sender) else { return }
         onKeyCommand?(key)
     }
+
+    // MARK: - KeyBar install / visibility (T-iPad-3)
+
+    /// Install the KeyBar as `inputAccessoryView`, honoring the initial
+    /// visibility (hidden when a hardware keyboard makes it redundant).
+    func installKeyBar(_ bar: KeyBarView, visible: Bool) {
+        keyBar = bar
+        appliedKeyBarVisible = visible
+        inputAccessoryView = visible ? bar : nil
+    }
+
+    /// Apply a visibility change; a no-op when unchanged so no needless
+    /// `reloadInputViews()` (the KeyByteMap routing on `keyBar.onKey` is
+    /// untouched — the same bar is only detached/re-attached).
+    func setKeyBarVisible(_ visible: Bool) {
+        guard visible != appliedKeyBarVisible else { return }
+        appliedKeyBarVisible = visible
+        inputAccessoryView = visible ? keyBar : nil
+        reloadInputViews()
+    }
+
+    // MARK: - Pointer context menu (T-iPad-3, iPad only)
+
+    /// Install the secondary-click / long-press context menu — iPad only, so
+    /// iPhone long-press keeps SwiftTerm's native selection gesture (zero
+    /// regression). The delegate builds a fresh model per presentation so the
+    /// copy item reflects the live selection.
+    func installPointerContextMenuIfSupported(
+        onNewInCwd: (@MainActor () -> Void)?,
+        onKill: (@MainActor () -> Void)?
+    ) {
+        // `UIDevice.current.userInterfaceIdiom` (not `traitCollection`, which can
+        // be `.unspecified` before the view joins a window at makeUIView time).
+        guard TerminalContextMenu.isPointerMenuEnabled(
+            idiom: UIDevice.current.userInterfaceIdiom
+        ) else { return }
+        let delegate = TerminalContextMenuInteractionDelegate { [weak self] in
+            TerminalContextMenuModel(
+                onNewInCwd: onNewInCwd,
+                onKill: onKill,
+                onCopySelection: { [weak self] in self?.copySelectionToPasteboard() },
+                hasSelection: { [weak self] in self?.hasActiveSelection ?? false }
+            )
+        }
+        contextMenuDelegate = delegate
+        addInteraction(UIContextMenuInteraction(delegate: delegate))
+    }
+
+    /// Whether a selection exists — reuses SwiftTerm's own `copy` eligibility
+    /// (`canPerformAction` returns `selection.active`); pure read, no bytes.
+    var hasActiveSelection: Bool {
+        canPerformAction(#selector(UIResponderStandardEditActions.copy(_:)), withSender: nil)
+    }
+
+    /// Copy the current selection via SwiftTerm's own `copy(_:)` (selection →
+    /// `UIPasteboard`). Pure UI: it never writes to the PTY, so the byte stream
+    /// is untouched (invariant preserved — same as pointer hover highlight).
+    func copySelectionToPasteboard() {
+        copy(nil)
+    }
 }