feat: dashboard redesign with light/dark appearance toggle

Replaces the old Smart Scan landing with a storage-led dashboard:

  - circular gauge showing % of disk used; gradient turns orange/red
    once usage crosses 85%
  - free-space hero numerals with a stacked usage bar (used / junk /
    purgeable) and a legend
  - four stat tiles (Free Space, Junk Found, Apps, Purgeable)
  - contextual suggestion cards — surfaces the largest pending category
    and an FDA nudge when access is missing; nothing is shown when
    there are no real suggestions
  - same surface for scanning/completed/cleaning/cleaned states with
    an animated rotating gauge during scans

Sidebar gets tinted icon tiles per row, capsule size badges per
category, and a persistent system-health footer that turns orange
when FDA isn't granted. Category detail pages get a hero card on
top showing the tinted icon, description, item count + size, and
the rescan action.

The flat orange FDA bar is replaced with a gradient toast card that
matches the dashboard surfaces. Toolbar gets a 3-segment appearance
pill (system / light / dark) with an animated indicator that slides
between segments — backed by a ThemeManager whose preference lives
in AppStorage so it persists.

docs/ui-prototype/{old,new}.html are clickable HTML mockups of the
previous and proposed designs, included for design review.

Author: livit

PureMac.xcodeproj/project.pbxproj

@@ -15,14 +15,16 @@
 		47C5ECD49C4DD75F271DB6CE /* StringNormalization.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D3AC5F17D7CA94FAB1E8D7A /* StringNormalization.swift */; };
 		48D1431A7C99C19EEBDB056B /* CleaningEngine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2A8DE5D45BA19E2670B57DC5 /* CleaningEngine.swift */; };
 		4F754D89F4CE5142BE384062 /* AppConstants.swift in Sources */ = {isa = PBXBuildFile; fileRef = F31F91226CDCFBB8E303B7DA /* AppConstants.swift */; };
+		535B23C0108C06475215B8E8 /* AppTheme.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1AB003A7751F05727DBFD1A5 /* AppTheme.swift */; };
 		75B5F0401D37F2872B1AD85A /* AppListView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 60E6BC61614B27C065BB18C9 /* AppListView.swift */; };
 		76B132F9C499225D33E0D075 /* EmptyStateView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 424F7B28624C271620E13BBC /* EmptyStateView.swift */; };
 		826A750D2D7EC14C2AE306A3 /* Models.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3667D46D8E2004EB4D73835A /* Models.swift */; };
 		8947F0CE448791BD50EECF46 /* Conditions.swift in Sources */ = {isa = PBXBuildFile; fileRef = CB94E06E145558123BB5BFB3 /* Conditions.swift */; };
 		93743B036059418560D876E6 /* SettingsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3A8D39C3C250F26302EC45AB /* SettingsView.swift */; };
+		95278ABDCF5F4D6AC60503B1 /* AppearancePill.swift in Sources */ = {isa = PBXBuildFile; fileRef = 92259B3E9F4468865F15DEEC /* AppearancePill.swift */; };
 		9AA80E035DF7B33F6EE118DF /* AppState.swift in Sources */ = {isa = PBXBuildFile; fileRef = CED1B71D5F9510582E869CFD /* AppState.swift */; };
 		9BB5AAA574AFED6C27A3F8E2 /* AppPathFinder.swift in Sources */ = {isa = PBXBuildFile; fileRef = AC0FEE7141871ED5F9E36121 /* AppPathFinder.swift */; };
-		A89DF967EC9E5E8123B2925A /* SmartScanView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 11BA091943263913276F3CCF /* SmartScanView.swift */; };
+		A2AE68CC75CB72D6B10CBDF5 /* DashboardView.swift in Sources */ = {isa = PBXBuildFile; fileRef = F661A0F64CF93E482CB1728F /* DashboardView.swift */; };
 		A9C3A1F643C26930F442E729 /* OrphanSafetyPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4AE790496C936424EF98320A /* OrphanSafetyPolicy.swift */; };
 		B52938BBD11842631314543D /* CategoryDetailView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 10B0AF194677EAC1D5568785 /* CategoryDetailView.swift */; };
 		BC6C800216343438413349A3 /* OnboardingView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3D4FD34378988D430A582ED0 /* OnboardingView.swift */; };
@@ -42,7 +44,7 @@
 		01B2C5F66B6D812572BD4F05 /* CLI.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CLI.swift; sourceTree = "<group>"; };
 		02E502E2B5C6AECC76E5CFEF /* zh-Hant */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = "zh-Hant"; path = "zh-Hant.lproj/Localizable.strings"; sourceTree = "<group>"; };
 		10B0AF194677EAC1D5568785 /* CategoryDetailView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CategoryDetailView.swift; sourceTree = "<group>"; };
-		11BA091943263913276F3CCF /* SmartScanView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SmartScanView.swift; sourceTree = "<group>"; };
+		1AB003A7751F05727DBFD1A5 /* AppTheme.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppTheme.swift; sourceTree = "<group>"; };
 		1D3AC5F17D7CA94FAB1E8D7A /* StringNormalization.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StringNormalization.swift; sourceTree = "<group>"; };
 		23486A54A82EE3865B784D1C /* AppInfoFetcher.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppInfoFetcher.swift; sourceTree = "<group>"; };
 		2641C6376DD6F5889F35510E /* zh-Hans */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = "zh-Hans"; path = "zh-Hans.lproj/Localizable.strings"; sourceTree = "<group>"; };
@@ -63,6 +65,7 @@
 		63581B70F9B10231964E3602 /* PureMacApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PureMacApp.swift; sourceTree = "<group>"; };
 		77D3D9A9BC52839E6D0A22BC /* Locations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Locations.swift; sourceTree = "<group>"; };
 		798B80977D14647A5691B0A0 /* AppFilesView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppFilesView.swift; sourceTree = "<group>"; };
+		92259B3E9F4468865F15DEEC /* AppearancePill.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppearancePill.swift; sourceTree = "<group>"; };
 		9F04B811BB0012F6D2F07F91 /* en */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = en; path = en.lproj/Localizable.strings; sourceTree = "<group>"; };
 		9F510F232341EE18F11DC934 /* MainWindow.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainWindow.swift; sourceTree = "<group>"; };
 		A711CDF5285F68775D9B5513 /* ScanEngine.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ScanEngine.swift; sourceTree = "<group>"; };
@@ -75,6 +78,7 @@
 		E866A1541D289C69144A5E62 /* FullDiskAccessManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FullDiskAccessManager.swift; sourceTree = "<group>"; };
 		EEF15CB1B8EFCA78EF491824 /* ScanError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ScanError.swift; sourceTree = "<group>"; };
 		F31F91226CDCFBB8E303B7DA /* AppConstants.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppConstants.swift; sourceTree = "<group>"; };
+		F661A0F64CF93E482CB1728F /* DashboardView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DashboardView.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXGroup section */
@@ -107,9 +111,9 @@
 			isa = PBXGroup;
 			children = (
 				10B0AF194677EAC1D5568785 /* CategoryDetailView.swift */,
+				F661A0F64CF93E482CB1728F /* DashboardView.swift */,
 				9F510F232341EE18F11DC934 /* MainWindow.swift */,
 				3D4FD34378988D430A582ED0 /* OnboardingView.swift */,
-				11BA091943263913276F3CCF /* SmartScanView.swift */,
 				DAD2EC78EB98016ADA27D114 /* Apps */,
 				8AE26715B5748307483A1A5E /* Components */,
 				9D3C2DC382F5D4B77DFD218B /* Orphans */,
@@ -148,6 +152,8 @@
 		8AE26715B5748307483A1A5E /* Components */ = {
 			isa = PBXGroup;
 			children = (
+				92259B3E9F4468865F15DEEC /* AppearancePill.swift */,
+				1AB003A7751F05727DBFD1A5 /* AppTheme.swift */,
 				424F7B28624C271620E13BBC /* EmptyStateView.swift */,
 			);
 			path = Components;
@@ -201,11 +207,11 @@
 			children = (
 				B2EA41E1096FA8E3B916AD13 /* Assets.xcassets */,
 				46660271CFF167AB0FE7371D /* Info.plist */,
+				241E0895B09C71AB423B2F9E /* Localizable.strings */,
 				5664D2BDAEAA9AE3A53DB364 /* PureMac.entitlements */,
 				63581B70F9B10231964E3602 /* PureMacApp.swift */,
 				D4333B07691BD85CAE0E5B15 /* Core */,
 				7C1729F88C0E5563E1A3DB40 /* Extensions */,
-				241E0895B09C71AB423B2F9E /* Localizable.strings */,
 				F283C00EB52AB140F61500A3 /* Logic */,
 				3CF46713F75B81F0F86D1C6F /* Models */,
 				6184B2EC3D01E6E95633406E /* Services */,
@@ -273,6 +279,7 @@
 				};
 			};
 			buildConfigurationList = 2ABAFAE07AA42044AE58F688 /* Build configuration list for PBXProject "PureMac" */;
+			compatibilityVersion = "Xcode 14.0";
 			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
@@ -286,7 +293,6 @@
 			mainGroup = 13CF0676D0E93925F46C13AA;
 			minimizedProjectReferenceProxies = 1;
 			preferredProjectObjectVersion = 77;
-			productRefGroup = 4562CA9E5625FA4EEEFECB6D /* Products */;
 			projectDirPath = "";
 			projectRoot = "";
 			targets = (
@@ -318,10 +324,13 @@
 				75B5F0401D37F2872B1AD85A /* AppListView.swift in Sources */,
 				9BB5AAA574AFED6C27A3F8E2 /* AppPathFinder.swift in Sources */,
 				9AA80E035DF7B33F6EE118DF /* AppState.swift in Sources */,
+				535B23C0108C06475215B8E8 /* AppTheme.swift in Sources */,
+				95278ABDCF5F4D6AC60503B1 /* AppearancePill.swift in Sources */,
 				F2FA881A4B2209CC2A6342FB /* CLI.swift in Sources */,
 				B52938BBD11842631314543D /* CategoryDetailView.swift in Sources */,
 				48D1431A7C99C19EEBDB056B /* CleaningEngine.swift in Sources */,
 				8947F0CE448791BD50EECF46 /* Conditions.swift in Sources */,
+				A2AE68CC75CB72D6B10CBDF5 /* DashboardView.swift in Sources */,
 				76B132F9C499225D33E0D075 /* EmptyStateView.swift in Sources */,
 				2253F11BDF561B617439C96B /* FullDiskAccessManager.swift in Sources */,
 				E60B0A2C5D0A6CAE35BF4DFB /* Locations.swift in Sources */,
@@ -336,7 +345,6 @@
 				D50EB059E741011EB2523731 /* ScanError.swift in Sources */,
 				27F449EDD1B082FE11FEC9DF /* SchedulerService.swift in Sources */,
 				93743B036059418560D876E6 /* SettingsView.swift in Sources */,
-				A89DF967EC9E5E8123B2925A /* SmartScanView.swift in Sources */,
 				47C5ECD49C4DD75F271DB6CE /* StringNormalization.swift in Sources */,
 				340E424F759ACCDE7372F99F /* Theme.swift in Sources */,
 			);

PureMac/Views/CategoryDetailView.swift

@@ -13,15 +13,22 @@ struct CategoryDetailView: View {
     }
 
     var body: some View {
-        Group {
-            if let result = result {
-                if result.items.isEmpty {
-                    EmptyStateView("All Clean", systemImage: "checkmark.circle", description: "No junk files found in this category.")
+        VStack(spacing: 0) {
+            heroCard
+                .padding(.horizontal, 20)
+                .padding(.top, 16)
+                .padding(.bottom, 12)
+
+            Group {
+                if let result = result {
+                    if result.items.isEmpty {
+                        EmptyStateView("All Clean", systemImage: "checkmark.circle", description: "No junk files found in this category.")
+                    } else {
+                        fileList(result)
+                    }
                 } else {
-                    fileList(result)
+                    EmptyStateView("Not Scanned", systemImage: category.icon, description: "Run a scan to analyze this category.", action: { appState.scanSingleCategory(category) }, actionLabel: "Scan Now")
                 }
-            } else {
-                EmptyStateView("Not Scanned", systemImage: category.icon, description: "Run a scan to analyze this category.", action: { appState.scanSingleCategory(category) }, actionLabel: "Scan Now")
             }
         }
         .searchable(text: $searchText, prompt: "Filter files")
@@ -81,6 +88,47 @@ struct CategoryDetailView: View {
         }
     }
 
+    // MARK: - Hero
+
+    private var heroCard: some View {
+        let totalSize = result?.totalSize ?? 0
+        let itemCount = result?.itemCount ?? 0
+        let isScanning = appState.scanState.isActive
+
+        return CardSurface(padding: 18) {
+            HStack(alignment: .center, spacing: 16) {
+                IconTile(systemName: category.icon, tint: category.color, size: 56, corner: 14)
+
+                VStack(alignment: .leading, spacing: 4) {
+                    Text(category.rawValue)
+                        .font(.system(size: 22, weight: .bold))
+                    Text(category.description)
+                        .font(.system(size: 12))
+                        .foregroundStyle(.secondary)
+                    if itemCount > 0 {
+                        Text("\(itemCount) items · \(ByteCountFormatter.string(fromByteCount: totalSize, countStyle: .file))")
+                            .font(.system(size: 11.5, weight: .medium))
+                            .foregroundStyle(category.color)
+                            .padding(.top, 2)
+                    }
+                }
+
+                Spacer()
+
+                Button {
+                    appState.scanSingleCategory(category)
+                } label: {
+                    Label(isScanning ? "Scanning…" : (result == nil ? "Scan" : "Rescan"),
+                          systemImage: "arrow.clockwise")
+                        .font(.system(size: 12.5, weight: .semibold))
+                }
+                .buttonStyle(.bordered)
+                .controlSize(.large)
+                .disabled(isScanning)
+            }
+        }
+    }
+
     // MARK: - File List
 
     private func fileList(_ result: CategoryResult) -> some View {

PureMac/Views/Components/AppTheme.swift

@@ -0,0 +1,97 @@
+import SwiftUI
+
+/// User-overridable appearance setting that lives independently of the system
+/// preference, mirroring the prototype's titlebar light/dark toggle.
+enum AppearanceMode: String, CaseIterable, Identifiable {
+    case system, light, dark
+    var id: String { rawValue }
+
+    var label: String {
+        switch self {
+        case .system: return "System"
+        case .light: return "Light"
+        case .dark: return "Dark"
+        }
+    }
+
+    var icon: String {
+        switch self {
+        case .system: return "circle.lefthalf.filled"
+        case .light: return "sun.max.fill"
+        case .dark: return "moon.fill"
+        }
+    }
+
+    var colorScheme: ColorScheme? {
+        switch self {
+        case .system: return nil
+        case .light: return .light
+        case .dark: return .dark
+        }
+    }
+}
+
+@MainActor
+final class ThemeManager: ObservableObject {
+    static let shared = ThemeManager()
+
+    @AppStorage("PureMac.Appearance") private var rawValue: String = AppearanceMode.system.rawValue
+
+    var appearance: AppearanceMode {
+        get { AppearanceMode(rawValue: rawValue) ?? .system }
+        set { rawValue = newValue.rawValue; objectWillChange.send() }
+    }
+}
+
+/// Centralized accent palette. Keeping these in one place lets the dashboard
+/// and sidebar share semantic tints (cleanup orange, performance green, etc.)
+/// instead of scattered Color literals.
+enum Tint {
+    static let blue   = Color(red: 0.04, green: 0.52, blue: 1.00)
+    static let green  = Color(red: 0.18, green: 0.78, blue: 0.47)
+    static let orange = Color(red: 1.00, green: 0.62, blue: 0.04)
+    static let purple = Color(red: 0.69, green: 0.32, blue: 0.87)
+    static let pink   = Color(red: 1.00, green: 0.30, blue: 0.50)
+    static let cyan   = Color(red: 0.30, green: 0.80, blue: 0.95)
+    static let red    = Color(red: 1.00, green: 0.27, blue: 0.23)
+    static let yellow = Color(red: 1.00, green: 0.78, blue: 0.04)
+}
+
+/// Tinted square icon container used in the sidebar and on dashboard cards.
+struct IconTile: View {
+    let systemName: String
+    var tint: Color = Tint.blue
+    var size: CGFloat = 26
+    var corner: CGFloat = 7
+
+    var body: some View {
+        ZStack {
+            RoundedRectangle(cornerRadius: corner, style: .continuous)
+                .fill(tint.opacity(0.16))
+            Image(systemName: systemName)
+                .font(.system(size: size * 0.52, weight: .semibold))
+                .foregroundStyle(tint)
+        }
+        .frame(width: size, height: size)
+    }
+}
+
+/// Card surface used on the dashboard, suggestion list, and detail pages.
+struct CardSurface<Content: View>: View {
+    var padding: CGFloat = 16
+    @ViewBuilder var content: Content
+
+    var body: some View {
+        content
+            .padding(padding)
+            .background(
+                RoundedRectangle(cornerRadius: 14, style: .continuous)
+                    .fill(Color(nsColor: .controlBackgroundColor))
+            )
+            .overlay(
+                RoundedRectangle(cornerRadius: 14, style: .continuous)
+                    .strokeBorder(Color.primary.opacity(0.06), lineWidth: 0.5)
+            )
+            .shadow(color: .black.opacity(0.06), radius: 6, y: 2)
+    }
+}

PureMac/Views/Components/AppearancePill.swift

@@ -0,0 +1,38 @@
+import SwiftUI
+
+/// Inline 3-segment toggle (system / light / dark) with an animated active
+/// indicator that slides between segments. Replaces the SwiftUI `Menu` which
+/// looked like a generic dropdown affordance.
+struct AppearancePill: View {
+    @Binding var selection: AppearanceMode
+    @Namespace private var indicator
+
+    var body: some View {
+        HStack(spacing: 2) {
+            ForEach(AppearanceMode.allCases) { mode in
+                Button {
+                    withAnimation(.spring(response: 0.32, dampingFraction: 0.78)) {
+                        selection = mode
+                    }
+                } label: {
+                    Image(systemName: mode.icon)
+                        .font(.system(size: 12, weight: .semibold))
+                        .frame(width: 28, height: 22)
+                        .foregroundStyle(selection == mode ? Color.primary : .secondary)
+                        .background(
+                            ZStack {
+                                if selection == mode {
+                                    RoundedRectangle(cornerRadius: 6, style: .continuous)
+                                        .fill(Color.primary.opacity(0.10))
+                                        .matchedGeometryEffect(id: "indicator", in: indicator)
+                                }
+                            }
+                        )
+                        .contentShape(Rectangle())
+                }
+                .buttonStyle(.plain)
+                .help(mode.label)
+            }
+        }
+    }
+}