Refine compact window chrome and active panel controls

Sources/AgentWorkbench/TaskContextPanel.swift

@@ -72,7 +72,7 @@ struct TaskContextButton: View {
         Button { model.taskContextWindow.togglePage(.task, model: model) } label: {
             WorkbenchToolbarSymbol(name: "checklist")
                 .foregroundStyle(open ? WorkbenchTheme.accent : .secondary)
-        }.buttonStyle(.plain).help("任务面板").accessibilityLabel("任务面板")
+        }.buttonStyle(WorkbenchToolbarButtonStyle(selected: open)).help("任务面板").accessibilityLabel("任务面板")
             .accessibilityValue(open ? "已展开" : "已收起")
     }
 }

Sources/AgentWorkbench/WorkbenchHeader.swift

@@ -49,7 +49,8 @@ struct WorkbenchHeaderActions: View {
                         Button { model.toggleFileViewer() } label: {
                             WorkbenchToolbarSymbol(name: "folder")
                                 .foregroundStyle(model.taskContextWindow.isShowing(.files) ? WorkbenchTheme.accent : .secondary)
-                        }.buttonStyle(.plain).help("查看文件（只读）").accessibilityLabel("查看文件")
+                        }.buttonStyle(WorkbenchToolbarButtonStyle(selected: model.taskContextWindow.isShowing(.files)))
+                            .help("查看文件（只读）").accessibilityLabel("查看文件")
                             .accessibilityValue(model.taskContextWindow.isShowing(.files) ? "已展开" : "已收起")
                         TaskContextButton(model: model)
                     }

Sources/AgentWorkbench/WorkspaceInspector.swift

@@ -111,7 +111,7 @@ struct ChangesButton: View {
         Button { model.taskContextWindow.togglePage(.changes, model: model) } label: {
             WorkbenchToolbarSymbol(name: "plus.forwardslash.minus")
                 .foregroundStyle(open ? WorkbenchTheme.accent : .secondary)
-        }.buttonStyle(.plain).help("查看改动").accessibilityLabel("改动")
+        }.buttonStyle(WorkbenchToolbarButtonStyle(selected: open)).help("查看改动").accessibilityLabel("改动")
             .accessibilityValue(open ? "已展开" : "已收起")
     }
 }

Sources/AgentWorkbench/WorkspaceSplitView.swift

@@ -3,9 +3,9 @@ import SwiftUI
 import WorkbenchCore
 
 enum WorkbenchChrome {
-    /// Measured height of the hidden-title-bar window with the unified toolbar.
-    static let headerHeight: CGFloat = 52
-    static let symbolSize: CGFloat = 15
+    /// Compact native toolbar, with a small gutter above the reading sheet.
+    static let headerHeight: CGFloat = 40
+    static let symbolSize: CGFloat = 14
     static let controlSize: CGFloat = 32
     static let controlSpacing: CGFloat = 16
     static let labelSpacing: CGFloat = 8
@@ -40,6 +40,30 @@ struct WorkbenchToolbarSymbol: View {
     }
 }
 
+/// One quiet state treatment inside the shared toolbar glass, with no extra elevation.
+struct WorkbenchToolbarButtonStyle: ButtonStyle {
+    var selected = false
+
+    func makeBody(configuration: Configuration) -> some View {
+        ToolbarButton(configuration: configuration, selected: selected)
+    }
+
+    private struct ToolbarButton: View {
+        let configuration: ButtonStyleConfiguration
+        let selected: Bool
+        @State private var hovered = false
+
+        var body: some View {
+            configuration.label.background {
+                RoundedRectangle(cornerRadius: WorkbenchTheme.Radius.row, style: .continuous)
+                    .fill(Color.primary.opacity(configuration.isPressed ? WorkbenchTheme.Fill.pressed
+                        : selected ? WorkbenchTheme.Fill.selected : hovered ? WorkbenchTheme.Fill.hover : 0))
+                    .padding(2)
+            }.onHover { hovered = $0 }
+        }
+    }
+}
+
 /// One translucent window backdrop contains navigation and the toolbar. The
 /// workspace sheet floats above it and contains the reader and inspector; their hosts survive resizing.
 struct WorkspaceSplitView<Sidebar: View, Header: View, Actions: View, Content: View>: NSViewControllerRepresentable {
@@ -840,7 +864,7 @@ final class WorkbenchSplitController: NSSplitViewController {
         window.titlebarAppearsTransparent = true
         window.titlebarSeparatorStyle = .none
         window.styleMask.insert(.fullSizeContentView)
-        window.toolbarStyle = .unified
+        window.toolbarStyle = .unifiedCompact
         if appAppearance != .system { applyAppearance() }
         // The toolbar style sets the window's corner; the glass follows it.
         windowBackdropView?.updateCornerRadius()

Tests/HostLifecycleChecks/NativeDesignChecks.swift

@@ -306,6 +306,19 @@ import WorkbenchCore
         "title": fromTop(title), "actions": fromTop(toolbarActions),
         "sidebar": fromTop(split.floatingSidebarView), "conversation": fromTop(card),
     ]
+    let actualTitlebarHeight = window.frame.height - window.contentLayoutRect.height
+    precondition(window.toolbarStyle == .unifiedCompact && actualTitlebarHeight <= 44,
+                 "Use the native compact toolbar rather than sliding content underneath a tall toolbar: \(actualTitlebarHeight)")
+    let liveCardFrame = card.convert(card.bounds, to: nil)
+    let liveCardTop = window.frame.height - liveCardFrame.maxY
+    precondition(abs(liveCardTop - 44) < 1 && liveCardTop >= actualTitlebarHeight &&
+                 abs(liveCardFrame.minY - WorkspaceLayoutMetrics.frameInset) < 1,
+                 "The reading sheet must start at 44 pt with a clear toolbar and a balanced bottom gutter")
+    let closeFrame = fromTop(window.standardWindowButton(.closeButton))
+    for control in [title, toolbarActions, toggle].compactMap({ $0 }) {
+        precondition(abs((fromTop(control)["midY"] ?? 0) - (closeFrame["midY"] ?? 0)) < 2,
+                     "Title, sidebar toggle and actions must share the window controls' vertical center")
+    }
     print("Native window chrome: \(chrome)")
     if let folder = ProcessInfo.processInfo.environment["PERCH_DESIGN_CAPTURES"] {
         func rectangle(_ rect: NSRect) -> [String: Double] {

docs/design/ui-spec.md

@@ -84,9 +84,11 @@
   `isSidebarYieldingToInspector`）；此时点侧栏按钮会让侧栏浮回正文上方。更窄时右栏让出至少 320pt 阅读区，不覆盖回复或输入框。
 - **标题锚定窗格，阅读栏居中**：工具栏标题只显示文字，14pt medium，距卡片左侧 24pt；最大宽度 360pt，长标题单行尾部截断，悬停显示完整标题、Agent、机器和目录。标题恢复或更换后仍保持此对齐；正文、活动条和输入区在卡片当前可用宽度内居中。
   右栏展开或关闭、左右侧栏缩放后必须重新居中，不能把正文固定在左边。对话和草稿宿主保持挂载。
-  工具栏放在统一底板上，正文卡片从窗口顶部 56pt 开始；hosting root 不重复应用标题栏安全区。
+  工具栏放在统一底板上，使用系统紧凑样式，正文卡片从窗口顶部 44pt 开始；hosting root 不重复应用标题栏安全区。
 - **工具栏按钮一组胶囊**：改动、文件、任务面板和会话菜单共用一个玻璃胶囊，单个按钮不再各带底。前三项仅显示图标：改动采用加减号、文件采用文件夹、任务采用清单；保留悬停提示与辅助功能名称，不显示常驻文字。会话菜单保留省略号。整组固定在窗口右缘，不随检查器开合向中间漂移。
   机器和 Agent 只在输入框底部显示，标题旁不再重复。
+  图标统一为 14pt 常规字重，保留 32pt 点击区域；改动、文件、任务哪个已打开，哪个显示内缩的轻量选中底色。
+  选中底色与悬停、按压分级，不为每个按钮增加独立玻璃或阴影。
 - **模型必须可见**：输入框底部明确显示实际模型名及独立的思考强度选择器，不能用 Agent 名替换模型名。
   运行环境作为次级信息；控制行不再给每组文字各套一层胶囊。窄窗口先将辅助控件移到第二行，保留模型与发送按钮。
 - **输入文字与正文对齐**：正文最大 680pt，输入框外壳最大 704pt，内部 12pt 留白；