fix: improve input source switching reliability on macOS 26

Input Source Pro/Models/ApplicationVM.swift

@@ -13,13 +13,14 @@ final class ApplicationVM: ObservableObject {
 
     let cancelBag = CancelBag()
     let preferencesVM: PreferencesVM
+    private var lastResolvedBrowserAppKinds = [String: AppKind]()
 
     lazy var windowAXNotificationPublisher = ApplicationVM
         .createWindowAXNotificationPublisher(preferencesVM: preferencesVM)
 
     init(preferencesVM: PreferencesVM) {
         self.preferencesVM = preferencesVM
-        appKind = .from(NSWorkspace.shared.frontmostApplication, preferencesVM: preferencesVM)
+        appKind = resolveAppKind(for: NSWorkspace.shared.frontmostApplication)
 
         activateAccessibilitiesForCurrentApp()
         watchApplicationChange()
@@ -59,10 +60,14 @@ extension ApplicationVM {
                 else { return Empty().eraseToAnyPublisher() }
 
                 guard NSApplication.isBrowser(app)
-                else { return Just(.from(app, preferencesVM: preferencesVM)).eraseToAnyPublisher() }
+                else {
+                    return Just(app)
+                        .compactMap { [weak self] in self?.resolveAppKind(for: $0) }
+                        .eraseToAnyPublisher()
+                }
 
                 return Timer
-                    .interval(seconds: 1)
+                    .interval(seconds: 0.05)
                     .prepend(Date())
                     .compactMap { _ in app.focusedUIElement(preferencesVM: preferencesVM) }
                     .first()
@@ -76,7 +81,7 @@ extension ApplicationVM {
                             .map { event in event.runningApp }
                     }
                     .prepend(app)
-                    .compactMap { app -> AppKind? in .from(app, preferencesVM: preferencesVM) }
+                    .compactMap { [weak self] in self?.resolveAppKind(for: $0) }
                     .eraseToAnyPublisher()
             }
             .removeDuplicates(by: { $0.isSameAppOrWebsite(with: $1, detectAddressBar: true) })
@@ -100,4 +105,30 @@ extension ApplicationVM {
             .sink { $0.getApp().activateAccessibilities() }
             .store(in: cancelBag)
     }
+
+    private func resolveAppKind(for app: NSRunningApplication?) -> AppKind? {
+        guard let app else { return nil }
+
+        let resolved = AppKind.from(app, preferencesVM: preferencesVM)
+
+        if let browserInfo = resolved.getBrowserInfo(),
+           !browserInfo.isFocusedOnAddressBar,
+           browserInfo.url != .newtab,
+           let bundleIdentifier = app.bundleIdentifier
+        {
+            lastResolvedBrowserAppKinds[bundleIdentifier] = resolved
+            return resolved
+        }
+
+        guard preferencesVM.isBrowserAndEnabled(app),
+              let bundleIdentifier = app.bundleIdentifier,
+              case .normal = resolved,
+              let fallback = lastResolvedBrowserAppKinds[bundleIdentifier]
+        else {
+            return resolved
+        }
+
+        logger.debug { "Reusing cached browser context for \(bundleIdentifier) while waiting for the focused tab to resolve." }
+        return fallback
+    }
 }

Input Source Pro/Models/IndicatorVM.swift

@@ -103,7 +103,7 @@ final class IndicatorVM: ObservableObject {
             .compactMap { $0 }
             .sink { [weak self] appKind in
                 guard let self = self else { return }
-                
+
                 let app = appKind.getApp()
                 if self.punctuationService.shouldEnableForApp(app) {
                     self.logger.debug { "Enabling English punctuation for app: \(app.localizedName ?? app.bundleIdentifier ?? "Unknown")" }
@@ -253,7 +253,7 @@ extension IndicatorVM {
 
                     return updateState(appKind: state.appKind, inputSource: inputSource, inputSourceChangeReason: .system)
                 case let .switchInputSourceByShortcut(inputSource):
-                    inputSourceVM.select(inputSource: inputSource)
+                    inputSourceVM.select(inputSource: inputSource, allowShortcutFallback: false)
 
                     return updateState(appKind: state.appKind, inputSource: inputSource, inputSourceChangeReason: .shortcut)
                 }

Input Source Pro/Models/InputSourceVM.swift

@@ -7,19 +7,24 @@ import CombineExt
 
 @MainActor
 class InputSourceVM: ObservableObject {
+    private struct SelectionRequest {
+        let inputSource: InputSource
+        let allowShortcutFallback: Bool
+    }
+
     let preferencesVM: PreferencesVM
 
     private var cancelBag = CancelBag()
 
-    private let selectInputSourceSubject = PassthroughSubject<InputSource, Never>()
+    private let selectInputSourceSubject = PassthroughSubject<SelectionRequest, Never>()
 
     private let inputSourceChangesSubject = PassthroughSubject<Void, Never>()
 
     let inputSourceChangesPublisher: AnyPublisher<InputSource, Never>
 
     init(preferencesVM: PreferencesVM) {
         self.preferencesVM = preferencesVM
-        
+
         inputSourceChangesPublisher = inputSourceChangesSubject
             .map { _ in InputSource.getCurrentInputSource() }
             .removeDuplicates()
@@ -30,22 +35,44 @@ class InputSourceVM: ObservableObject {
         selectInputSourceSubject
             .tap { [weak self] in
                 if let self {
-                    $0.select(useCJKVFix: self.preferencesVM.isUseCJKVFix())
+                    $0.inputSource.select(
+                        useCJKVFix: self.preferencesVM.isUseCJKVFix(),
+                        allowShortcutFallback: $0.allowShortcutFallback
+                    )
                 }
             }
             .flatMapLatest({ _ in
-                Timer
-                    .interval(seconds: 1)
-                    .eraseToAnyPublisher()
+                Publishers.MergeMany([
+                    Just(())
+                        .eraseToAnyPublisher(),
+                    Timer
+                        .delay(seconds: 0.05)
+                        .mapToVoid()
+                        .eraseToAnyPublisher(),
+                    Timer
+                        .delay(seconds: 0.15)
+                        .mapToVoid()
+                        .eraseToAnyPublisher(),
+                    Timer
+                        .delay(seconds: 0.3)
+                        .mapToVoid()
+                        .eraseToAnyPublisher()
+                ])
+                .eraseToAnyPublisher()
             })
             .sink { [weak self] _ in
                 self?.inputSourceChangesSubject.send(())
             }
             .store(in: cancelBag)
     }
 
-    func select(inputSource: InputSource) {
-        selectInputSourceSubject.send(inputSource)
+    func select(inputSource: InputSource, allowShortcutFallback: Bool = true) {
+        selectInputSourceSubject.send(
+            SelectionRequest(
+                inputSource: inputSource,
+                allowShortcutFallback: allowShortcutFallback
+            )
+        )
     }
 
     private func watchSystemNotification() {

Input Source Pro/Utilities/AppKit/AppRuleMenuItem.swift

@@ -42,7 +42,10 @@ class AppRuleMenuItem: NSMenuItem {
             )
         }
 
-        inputSource?.select(useCJKVFix: preferencesVM.isUseCJKVFix())
+        inputSource?.select(
+            useCJKVFix: preferencesVM.isUseCJKVFix(),
+            allowShortcutFallback: false
+        )
 
         watchChanges()
     }

Input Source Pro/Utilities/AppKit/BrowserRuleMenuItem.swift

@@ -55,7 +55,10 @@ class BrowserRuleMenuItem: NSMenuItem {
             )
         }
 
-        inputSource?.select(useCJKVFix: preferencesVM.isUseCJKVFix())
+        inputSource?.select(
+            useCJKVFix: preferencesVM.isUseCJKVFix(),
+            allowShortcutFallback: false
+        )
 
         watchChanges()
     }

Input Source Pro/Utilities/InputSource/InputSource.swift

@@ -70,8 +70,12 @@ class InputSource {
         }()
     }
 
-    func select(useCJKVFix: Bool) {
-        InputSourceSwitcher.switchToInputSource(self, useCJKVFix: useCJKVFix)
+    func select(useCJKVFix: Bool, allowShortcutFallback: Bool = true) {
+        InputSourceSwitcher.switchToInputSource(
+            self,
+            useCJKVFix: useCJKVFix,
+            allowShortcutFallback: allowShortcutFallback
+        )
     }
 
     private var normalizedInputModeID: String? {