macos: clean up the "installing" update state (#9170)

This includes multiple changes to clean up the "installing" state:

- Ghostty will not confirm quit, since the user has already confirmed
they want to restart to install the update.
- If termination fails for any reason, the popover has a button to retry
restarting.
- The copy and badge symbol have been updated to better match the
reality of the "installing" state.

<img width="1756" height="890" alt="CleanShot 2025-10-12 at 15 04 08@2x"
src="https://github.com/user-attachments/assets/1b769518-e15f-4758-be3b-c45163fa2603"
/>

AI written:
https://ampcode.com/threads/T-623d1030-419f-413f-a285-e79c86a4246b fully
understood.

macos/Sources/App/macOS/AppDelegate.swift

@@ -322,6 +322,12 @@ class AppDelegate: NSObject,
     func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
         let windows = NSApplication.shared.windows
         if (windows.isEmpty) { return .terminateNow }
+        
+        // If we've already accepted to install an update, then we don't need to
+        // confirm quit. The user is already expecting the update to happen.
+        if updateController.isInstalling {
+            return .terminateNow
+        }
 
         // This probably isn't fully safe. The isEmpty check above is aspirational, it doesn't
         // quite work with SwiftUI because windows are retained on close. So instead we check

macos/Sources/Features/Update/UpdateBadge.swift

@@ -32,7 +32,7 @@ struct UpdateBadge: View {
         case .extracting(let extracting):
             ProgressRingView(progress: min(1, max(0, extracting.progress)))
             
-        case .checking, .installing:
+        case .checking:
             if let iconName = model.iconName {
                 Image(systemName: iconName)
                     .rotationEffect(.degrees(rotationAngle))

macos/Sources/Features/Update/UpdateController.swift

@@ -17,6 +17,11 @@ class UpdateController {
         userDriver.viewModel
     }
     
+    /// True if we're installing an update.
+    var isInstalling: Bool {
+        installCancellable != nil
+    }
+    
     /// Initialize a new update controller.
     init() {
         let hostBundle = Bundle.main

macos/Sources/Features/Update/UpdateDriver.swift

@@ -172,7 +172,7 @@ class UpdateDriver: NSObject, SPUUserDriver {
     }
     
     func showInstallingUpdate(withApplicationTerminated applicationTerminated: Bool, retryTerminatingApplication: @escaping () -> Void) {
-        viewModel.state = .installing
+        viewModel.state = .installing(.init(retryTerminatingApplication: retryTerminatingApplication))
         
         if !hasUnobtrusiveTarget {
             standard.showInstallingUpdate(withApplicationTerminated: applicationTerminated, retryTerminatingApplication: retryTerminatingApplication)

macos/Sources/Features/Update/UpdatePopoverView.swift

@@ -38,8 +38,8 @@ struct UpdatePopoverView: View {
             case .readyToInstall(let ready):
                 ReadyToInstallView(ready: ready, dismiss: dismiss)
                 
-            case .installing:
-                InstallingView()
+            case .installing(let installing):
+                InstallingView(installing: installing, dismiss: dismiss)
                 
             case .notFound(let notFound):
                 NotFoundView(notFound: notFound, dismiss: dismiss)
@@ -313,18 +313,31 @@ fileprivate struct ReadyToInstallView: View {
 }
 
 fileprivate struct InstallingView: View {
+    let installing: UpdateState.Installing
+    let dismiss: DismissAction
+    
     var body: some View {
-        VStack(alignment: .leading, spacing: 8) {
-            HStack(spacing: 10) {
-                ProgressView()
-                    .controlSize(.small)
-                Text("Installing…")
+        VStack(alignment: .leading, spacing: 16) {
+            VStack(alignment: .leading, spacing: 8) {
+                Text("Restart Required")
                     .font(.system(size: 13, weight: .semibold))
+                
+                Text("The update is ready. Please restart the application to complete the installation.")
+                    .font(.system(size: 11))
+                    .foregroundColor(.secondary)
+                    .fixedSize(horizontal: false, vertical: true)
             }
             
-            Text("The application will relaunch shortly.")
-                .font(.system(size: 11))
-                .foregroundColor(.secondary)
+            HStack {
+                Spacer()
+                Button("Restart Now") {
+                    installing.retryTerminatingApplication()
+                    dismiss()
+                }
+                .keyboardShortcut(.defaultAction)
+                .buttonStyle(.borderedProminent)
+                .controlSize(.small)
+            }
         }
         .padding(16)
     }

macos/Sources/Features/Update/UpdateSimulator.swift

@@ -28,6 +28,9 @@ enum UpdateSimulator {
     /// User cancels while checking: checking (1s) → cancels → idle
     case cancelDuringChecking
     
+    /// Shows the installing state with restart button: installing (stays until dismissed)
+    case installing
+    
     func simulate(with viewModel: UpdateViewModel) {
         switch self {
         case .happyPath:
@@ -44,6 +47,8 @@ enum UpdateSimulator {
             simulateCancelDuringDownload(viewModel)
         case .cancelDuringChecking:
             simulateCancelDuringChecking(viewModel)
+        case .installing:
+            simulateInstalling(viewModel)
         }
     }
     
@@ -260,10 +265,10 @@ enum UpdateSimulator {
                         viewModel.state = .readyToInstall(.init(
                             reply: { choice in
                                 if choice == .install {
-                                    viewModel.state = .installing
-                                    DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
+                                    viewModel.state = .installing(.init(retryTerminatingApplication: {
+                                        print("Restart button clicked in simulator - resetting to idle")
                                         viewModel.state = .idle
-                                    }
+                                    }))
                                 } else {
                                     viewModel.state = .idle
                                 }
@@ -274,4 +279,11 @@ enum UpdateSimulator {
             }
         }
     }
+    
+    private func simulateInstalling(_ viewModel: UpdateViewModel) {
+        viewModel.state = .installing(.init(retryTerminatingApplication: {
+            print("Restart button clicked in simulator - resetting to idle")
+            viewModel.state = .idle
+        }))
+    }
 }

macos/Sources/Features/Update/UpdateViewModel.swift

@@ -33,7 +33,7 @@ class UpdateViewModel: ObservableObject {
         case .readyToInstall:
             return "Install Update"
         case .installing:
-            return "Installing…"
+            return "Restart to Complete Update"
         case .notFound:
             return "No Updates Available"
         case .error(let err):
@@ -72,7 +72,7 @@ class UpdateViewModel: ObservableObject {
         case .readyToInstall:
             return "checkmark.circle.fill"
         case .installing:
-            return "gear"
+            return "power.circle"
         case .notFound:
             return "info.circle"
         case .error:
@@ -192,7 +192,7 @@ enum UpdateState: Equatable {
     case downloading(Downloading)
     case extracting(Extracting)
     case readyToInstall(ReadyToInstall)
-    case installing
+    case installing(Installing)
     
     var isIdle: Bool {
         if case .idle = self { return true }
@@ -382,4 +382,8 @@ enum UpdateState: Equatable {
     struct ReadyToInstall {
         let reply: @Sendable (SPUUserUpdateChoice) -> Void
     }
+    
+    struct Installing {
+        let retryTerminatingApplication: () -> Void
+    }
 }

macos/Tests/Update/UpdateStateTests.swift

@@ -25,8 +25,8 @@ struct UpdateStateTests {
     }
     
     @Test func testInstallingEquality() {
-        let state1: UpdateState = .installing
-        let state2: UpdateState = .installing
+        let state1: UpdateState = .installing(.init(retryTerminatingApplication: {}))
+        let state2: UpdateState = .installing(.init(retryTerminatingApplication: {}))
         #expect(state1 == state2)
     }
     

macos/Tests/Update/UpdateViewModelTests.swift

@@ -58,8 +58,8 @@ struct UpdateViewModelTests {
     
     @Test func testInstallingText() {
         let viewModel = UpdateViewModel()
-        viewModel.state = .installing
-        #expect(viewModel.text == "Installing…")
+        viewModel.state = .installing(.init(retryTerminatingApplication: {}))
+        #expect(viewModel.text == "Restart to Complete Update")
     }
     
     @Test func testNotFoundText() {