Implement v4.6.0: sweep Live Activity, share extension, iPad split view, actionable notifications

- Sweep Live Activity: SweepActivityAttributes (Shared/), lock-screen + Dynamic
  Island UI in the widget extension, driven by SweepActivityController wired into
  the batch pipeline (begin/update/end); NSSupportsLiveActivities in Info.plist.
- Share extension (DomainDigShareExtension): accepts a web URL from the share
  sheet, extracts the host, and hands it to the app via the App Group inbox
  (DomainDigShareInbox); the app consumes it on activation and inspects it.
- iPad layout: RootTabView uses NavigationSplitView in the regular size class
  and the tab bar in compact.
- Actionable notifications: per-domain threadIdentifier grouping, a Re-inspect
  action, and tap routing into the domain detail via the intent router.
- Bump version to 4.6.0 (build 38) across app, widget, and share targets.

1 files changed, 93 insertions, 43 deletions

diff --git a/DomainDig/RootTabView.swift b/DomainDig/RootTabView.swift
index 9823d37..db1f524 100644
--- a/DomainDig/RootTabView.swift
+++ b/DomainDig/RootTabView.swift
@@ -1,15 +1,36 @@
 import SwiftUI
 
-private enum RootTab: Hashable {
+private enum RootTab: Hashable, CaseIterable {
     case dashboard
     case audit
     case history
     case inspect
     case settings
+
+    var title: String {
+        switch self {
+        case .dashboard: return "Dashboard"
+        case .audit: return "Audit"
+        case .history: return "History"
+        case .inspect: return "Inspect"
+        case .settings: return "Settings"
+        }
+    }
+
+    var systemImage: String {
+        switch self {
+        case .dashboard: return "square.grid.2x2"
+        case .audit: return "checklist"
+        case .history: return "clock.arrow.trianglehead.counterclockwise.rotate.90"
+        case .inspect: return "magnifyingglass"
+        case .settings: return "gearshape"
+        }
+    }
 }
 
 struct RootTabView: View {
     @Bindable var viewModel: DomainViewModel
+    @Environment(\.horizontalSizeClass) private var horizontalSizeClass
     @State private var purchaseService = PurchaseService.shared
     @State private var intentRouter = DomainDigIntentRouter.shared
     @State private var detailDomain: TrackedDomain?
@@ -18,44 +39,12 @@ struct RootTabView: View {
     var body: some View {
         let _ = purchaseService.currentTier
 
-        TabView(selection: $selectedTab) {
-            NavigationStack {
-                DashboardView(viewModel: viewModel)
-            }
-            .tabItem {
-                Label("Dashboard", systemImage: "square.grid.2x2")
-            }
-            .tag(RootTab.dashboard)
-
-            NavigationStack {
-                AuditListView(viewModel: viewModel)
-            }
-            .tabItem {
-                Label("Audit", systemImage: "checklist")
-            }
-            .tag(RootTab.audit)
-
-            NavigationStack {
-                HistoryView(viewModel: viewModel)
-            }
-            .tabItem {
-                Label("History", systemImage: "clock.arrow.trianglehead.counterclockwise.rotate.90")
-            }
-            .tag(RootTab.history)
-
-            ContentView(viewModel: viewModel)
-                .tabItem {
-                    Label("Inspect", systemImage: "magnifyingglass")
-                }
-                .tag(RootTab.inspect)
-
-            NavigationStack {
-                SettingsView(viewModel: viewModel)
-            }
-            .tabItem {
-                Label("Settings", systemImage: "gearshape")
+        Group {
+            if horizontalSizeClass == .regular {
+                splitLayout
+            } else {
+                tabLayout
             }
-            .tag(RootTab.settings)
         }
         .sheet(isPresented: Binding(
             get: { viewModel.isPaywallPresented },
@@ -79,16 +68,16 @@ struct RootTabView: View {
                 }
             )
         }
-        .onChange(of: purchaseService.currentTier) { _, newValue in
-            if newValue != .free, selectedTab == .inspect, viewModel.trackedDomains.isEmpty == false {
-                selectedTab = .dashboard
-            }
-        }
         .sheet(item: $detailDomain) { trackedDomain in
             NavigationStack {
                 TrackedDomainDetailView(viewModel: viewModel, trackedDomain: trackedDomain)
             }
         }
+        .onChange(of: purchaseService.currentTier) { _, newValue in
+            if newValue != .free, selectedTab == .inspect, viewModel.trackedDomains.isEmpty == false {
+                selectedTab = .dashboard
+            }
+        }
         .onOpenURL { url in
             guard let action = DomainDigDeepLink.action(from: url) else { return }
             perform(action)
@@ -101,6 +90,67 @@ struct RootTabView: View {
         }
     }
 
+    // MARK: Layouts
+
+    /// Compact (iPhone, iPad slide-over): the classic tab bar.
+    private var tabLayout: some View {
+        TabView(selection: $selectedTab) {
+            ForEach(RootTab.allCases, id: \.self) { tab in
+                section(for: tab)
+                    .tabItem {
+                        Label(tab.title, systemImage: tab.systemImage)
+                    }
+                    .tag(tab)
+            }
+        }
+    }
+
+    /// Regular width (iPad, large iPhone landscape): two-column split view.
+    private var splitLayout: some View {
+        NavigationSplitView {
+            List(RootTab.allCases, id: \.self, selection: sidebarSelection) { tab in
+                Label(tab.title, systemImage: tab.systemImage)
+                    .tag(tab)
+            }
+            .navigationTitle("DomainDig")
+        } detail: {
+            section(for: selectedTab)
+        }
+    }
+
+    private var sidebarSelection: Binding<RootTab?> {
+        Binding(
+            get: { selectedTab },
+            set: { selectedTab = $0 ?? selectedTab }
+        )
+    }
+
+    @ViewBuilder
+    private func section(for tab: RootTab) -> some View {
+        switch tab {
+        case .dashboard:
+            NavigationStack {
+                DashboardView(viewModel: viewModel)
+            }
+        case .audit:
+            NavigationStack {
+                AuditListView(viewModel: viewModel)
+            }
+        case .history:
+            NavigationStack {
+                HistoryView(viewModel: viewModel)
+            }
+        case .inspect:
+            ContentView(viewModel: viewModel)
+        case .settings:
+            NavigationStack {
+                SettingsView(viewModel: viewModel)
+            }
+        }
+    }
+
+    // MARK: Intent / deep-link routing
+
     private func consume(_ action: DomainDigDeepLink.Action?) {
         guard let action else { return }
         intentRouter.pendingAction = nil