perf(keywords): Speed up sidebar navigation

.gitignore

@@ -30,3 +30,6 @@ dist/
 # Xcode user state
 *.xcuserdatad
 *.xcuserstate
+
+# Local reports, audits, and scratch work
+/.local/

OpenASO/App/RootSidebarView.swift

@@ -43,7 +43,9 @@ struct RootSidebarView: View {
     }
 
     private var keywordTrackCountsByAppStoreID: [Int64: Int] {
-        Dictionary(grouping: trackedKeywords, by: \.appStoreID).mapValues(\.count)
+        trackedKeywords.reduce(into: [:]) { counts, track in
+            counts[track.appStoreID, default: 0] += 1
+        }
     }
 
     var body: some View {
@@ -158,7 +160,8 @@ struct RootSidebarView: View {
     }
 
     private var appList: some View {
-        Group {
+        let keywordCounts = keywordTrackCountsByAppStoreID
+        return Group {
             if trackedApps.isEmpty && appFolders.isEmpty {
                 ContentUnavailableView(
                     "No Apps Yet",
@@ -178,7 +181,7 @@ struct RootSidebarView: View {
                             )
                         ) {
                             ForEach(sortedApps(in: folder)) { trackedApp in
-                                appRow(for: trackedApp)
+                                appRow(for: trackedApp, keywordTrackCount: keywordCounts[trackedApp.appStoreID, default: 0])
                             }
                         } label: {
                             folderLabel(for: folder)
@@ -200,7 +203,7 @@ struct RootSidebarView: View {
                     }
 
                     ForEach(unfiledApps) { trackedApp in
-                        appRow(for: trackedApp)
+                        appRow(for: trackedApp, keywordTrackCount: keywordCounts[trackedApp.appStoreID, default: 0])
                     }
                 }
                 .listStyle(.sidebar)
@@ -323,10 +326,9 @@ struct RootSidebarView: View {
         }
     }
 
-    private func appRow(for trackedApp: TrackedApp) -> some View {
+    private func appRow(for trackedApp: TrackedApp, keywordTrackCount: Int) -> some View {
         let appStoreID = trackedApp.appStoreID
         let draggableID = String(appStoreID)
-        let keywordTrackCount = keywordTrackCountsByAppStoreID[appStoreID, default: 0]
 
         return HStack(spacing: 12) {
             AppIconView(

OpenASO/App/RootView.swift

@@ -11,7 +11,7 @@ struct RootView: View {
 
     var body: some View {
         NavigationSplitView {
-            RootSidebarView(selectedApp: $selectedApp)
+            RootSidebarView(selectedApp: appSelection)
                 .navigationSplitViewColumnWidth(min: 280, ideal: 320)
         } detail: {
             RootDetailView(selectedApp: selectedApp)
@@ -59,6 +59,17 @@ struct RootView: View {
         }
     }
 
+    private var appSelection: Binding<TrackedApp?> {
+        Binding(
+            get: { selectedApp },
+            set: { app in
+                var transaction = Transaction(animation: nil)
+                transaction.disablesAnimations = true
+                withTransaction(transaction) { selectedApp = app }
+            }
+        )
+    }
+
     private static var isRunningUnderTests: Bool {
         ProcessInfo.processInfo.environment["XCTestConfigurationFilePath"] != nil
     }

OpenASO/Features/AppDetail/AppDetailView.swift

@@ -66,20 +66,23 @@ struct AppDetailView: View {
                     refreshToken: ratingsRefreshToken
                 )
             } else {
-                AppKeywordsView(
-                    trackedApp: trackedApp,
-                    searchText: searchText,
-                    selectedStorefrontFilter: selectedStorefrontFilter,
-                    selectedDateRange: keywordWorkspaceState.selectedDateRange,
-                    selectedPlatformFilter: keywordWorkspaceState.selectedPlatformFilter,
-                    popularityFilterRange: keywordWorkspaceState.popularityFilterRange,
-                    difficultyFilterRange: keywordWorkspaceState.difficultyFilterRange,
-                    positionFilterRange: keywordWorkspaceState.positionFilterRange,
-                    changeFilterRange: keywordWorkspaceState.changeFilterRange,
-                    showsOnlyChangedKeywords: keywordWorkspaceState.showsOnlyChangedKeywords,
-                    refreshToken: keywordRefreshToken,
-                    reportError: setErrorMessage
-                )
+                KeywordWorkspaceTabs(selectedApp: trackedApp, trackedApps: trackedApps) { app, isActive in
+                    AppKeywordsView(
+                        trackedApp: app,
+                        isActive: isActive,
+                        searchText: searchText,
+                        selectedStorefrontFilter: selectedStorefrontFilter,
+                        selectedDateRange: keywordWorkspaceState.selectedDateRange,
+                        selectedPlatformFilter: keywordWorkspaceState.selectedPlatformFilter,
+                        popularityFilterRange: keywordWorkspaceState.popularityFilterRange,
+                        difficultyFilterRange: keywordWorkspaceState.difficultyFilterRange,
+                        positionFilterRange: keywordWorkspaceState.positionFilterRange,
+                        changeFilterRange: keywordWorkspaceState.changeFilterRange,
+                        showsOnlyChangedKeywords: keywordWorkspaceState.showsOnlyChangedKeywords,
+                        refreshToken: keywordRefreshToken,
+                        reportError: setErrorMessage
+                    )
+                }
             }
         }
         .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .topLeading)

OpenASO/Features/AppDetail/Keywords/AppKeywordsView.swift

@@ -8,6 +8,7 @@ struct AppKeywordsView: View {
     @Query private var tracks: [TrackedAppKeyword]
 
     let trackedApp: TrackedApp
+    let isActive: Bool
     let searchText: String
     let selectedStorefrontFilter: StorefrontFilter
     let selectedDateRange: TrendDateRange
@@ -24,6 +25,7 @@ struct AppKeywordsView: View {
 
     init(
         trackedApp: TrackedApp,
+        isActive: Bool = true,
         searchText: String,
         selectedStorefrontFilter: StorefrontFilter,
         selectedDateRange: TrendDateRange,
@@ -37,6 +39,7 @@ struct AppKeywordsView: View {
         reportError: @escaping (String) -> Void
     ) {
         self.trackedApp = trackedApp
+        self.isActive = isActive
         self.searchText = searchText
         self.selectedStorefrontFilter = selectedStorefrontFilter
         self.selectedDateRange = selectedDateRange
@@ -86,7 +89,8 @@ struct AppKeywordsView: View {
             dateRangeID: selectedDateRange.id,
             tracks: tracks.map { track in
                 KeywordWorkspaceProjection.MaterializationID.TrackIdentity(
-                    identityKey: track.identityKey
+                    identityKey: track.identityKey,
+                    notes: track.notes
                 )
             }
         )
@@ -146,6 +150,7 @@ struct AppKeywordsView: View {
         let storefronts = storefrontDefinitions
         KeywordWorkspaceContent(
             workspaceModel: workspaceModel,
+            isActive: isActive,
             targetMaterializationID: targetMaterializationID,
             filters: filters,
             hasTrackedKeywords: !queriedTracks.isEmpty,
@@ -156,7 +161,8 @@ struct AppKeywordsView: View {
             reportError: reportError
         )
         .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .topLeading)
-        .task(id: targetMaterializationID) {
+        .task(id: isActive ? targetMaterializationID : nil) {
+            guard isActive else { return }
             await materializeKeywordRows(
                 for: targetMaterializationID,
                 tracks: queriedTracks
@@ -168,6 +174,10 @@ struct AppKeywordsView: View {
         for targetMaterializationID: KeywordWorkspaceProjection.MaterializationID,
         tracks: [TrackedAppKeyword]
     ) async {
+        if workspaceModel.reuseMaterialization(for: targetMaterializationID, filters: filters) {
+            return
+        }
+
         let platformTracks = tracks.filter { selectedPlatformFilter.matches($0.platform) }
         let storefrontLookup = Dictionary(
             uniqueKeysWithValues: storefrontDefinitions.map { ($0.code, $0) }
@@ -217,6 +227,7 @@ private struct KeywordWorkspaceContent: View {
     @Environment(AppServices.self) private var services
 
     let workspaceModel: KeywordWorkspaceModel
+    let isActive: Bool
     let targetMaterializationID: KeywordWorkspaceProjection.MaterializationID
     let filters: KeywordWorkspaceProjection.Filters
     let hasTrackedKeywords: Bool
@@ -263,14 +274,17 @@ private struct KeywordWorkspaceContent: View {
             }
         }
         .background {
-            KeywordDataUpdateListener(
-                workspaceModel: workspaceModel,
-                appStoreID: trackedAppStoreID,
-                dateRange: selectedDateRange,
-                reportError: reportError
-            )
+            if isActive {
+                KeywordDataUpdateListener(
+                    workspaceModel: workspaceModel,
+                    appStoreID: trackedAppStoreID,
+                    dateRange: selectedDateRange,
+                    reportError: reportError
+                )
+            }
         }
-        .task(id: filterID) {
+        .task(id: isActive ? filterID : nil) {
+            guard isActive else { return }
             await workspaceModel.updateFilter(id: filterID) { rows, filters in
                 try await KeywordWorkspaceProjection.debouncedRows(
                     rows,
@@ -534,3 +548,49 @@ private extension Array {
         }
     }
 }
+
+// Keep the current app and two recent apps mounted so sidebar navigation does
+// not reconstruct hundreds of table cells. Evicted views release their state.
+private struct KeywordWorkspacePage<Content: View>: View {
+    let isActive: Bool
+    @ViewBuilder let content: Content
+
+    var body: some View {
+        content
+            // Opaque pages stay mounted behind the active one. Opacity zero
+            // lets SwiftUI discard their native table views.
+            .background(.background)
+            .allowsHitTesting(isActive)
+            .accessibilityHidden(!isActive)
+            .zIndex(isActive ? 1 : 0)
+    }
+}
+
+struct KeywordWorkspaceTabs<Content: View>: View {
+    let selectedApp: TrackedApp
+    let trackedApps: [TrackedApp]
+    @ViewBuilder let content: (TrackedApp, Bool) -> Content
+
+    @State private var recentAppIDs: [Int64] = []
+
+    var body: some View {
+        let selectedID = selectedApp.appStoreID
+        let recentApps = recentAppIDs
+            .filter { $0 != selectedID }
+            .compactMap { id in trackedApps.first { $0.appStoreID == id } }
+            .prefix(2)
+        let pages = ([selectedApp] + recentApps).sorted { $0.appStoreID < $1.appStoreID }
+
+        ZStack {
+            ForEach(pages) { app in
+                let isActive = app.appStoreID == selectedID
+                KeywordWorkspacePage(isActive: isActive) {
+                    content(app, isActive)
+                }
+            }
+        }
+        .onChange(of: selectedID, initial: true) {
+            recentAppIDs = [selectedID] + recentAppIDs.filter { $0 != selectedID }.prefix(2)
+        }
+    }
+}