Fix notification click launching second app instance

Makefile

@@ -24,4 +24,4 @@ run: build-app
 	open $(APP_PATH)
 
 run-isolated: build-isolated
-	open -n --env SHELLRAISER_APP_SUPPORT_SUBDIRECTORY=$(ISOLATED_APP_SUPPORT_SUBDIRECTORY) $(ISOLATED_APP_PATH)
+	open --env SHELLRAISER_APP_SUPPORT_SUBDIRECTORY=$(ISOLATED_APP_SUPPORT_SUBDIRECTORY) $(ISOLATED_APP_PATH)

Sources/Shellraiser/App/ShellraiserApp.swift

@@ -94,6 +94,17 @@ final class ShellraiserAppDelegate: NSObject, NSApplicationDelegate {
         ShellraiserScriptingController.shared.insertSurfaceConfiguration(configuration)
     }
 
+    /// Brings the main window to front when the dock icon is clicked with no visible windows.
+    func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
+        if !flag {
+            for window in sender.windows where window.canBecomeMain {
+                window.makeKeyAndOrderFront(nil)
+                break
+            }
+        }
+        return true
+    }
+
     /// Intercepts standard app termination and requires explicit user confirmation.
     func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
         guard confirmQuit() else {
@@ -112,15 +123,25 @@ struct ShellraiserApp: App {
     @StateObject private var manager: WorkspaceManager
 
     /// Disables native macOS window tabbing so the app's own pane tabs remain the only tab UI.
+    /// Exits immediately if another instance with the same bundle ID is already running,
+    /// activating the existing instance instead — guards against Launch Services conflicts.
     init() {
+        if let bundleID = Bundle.main.bundleIdentifier {
+            let others = NSRunningApplication.runningApplications(withBundleIdentifier: bundleID)
+                .filter { $0 != .current }
+            if let existing = others.first {
+                existing.activate()
+                exit(0)
+            }
+        }
         NSWindow.allowsAutomaticWindowTabbing = false
         let manager = WorkspaceManager()
         _manager = StateObject(wrappedValue: manager)
         ShellraiserScriptingController.shared.install(workspaceManager: manager)
     }
 
     var body: some Scene {
-        WindowGroup {
+        Window("Shellraiser", id: "main") {
             ContentView(manager: manager)
                 .frame(minWidth: 1100, minHeight: 760)
         }

Tests/ShellraiserTests/ShellraiserAppTests.swift

@@ -40,4 +40,20 @@ final class ShellraiserAppTests: WorkspaceTestCase {
         XCTAssertEqual(reply, .terminateCancel)
         XCTAssertFalse(manager.isTerminating)
     }
+
+    /// Verifies the delegate returns true (allow reopen handling) when no windows are visible,
+    /// so AppKit proceeds to make a window key — required for dock-click restoration.
+    func testApplicationShouldHandleReopenReturnsTrueWithNoVisibleWindows() {
+        let delegate = ShellraiserAppDelegate()
+        let result = delegate.applicationShouldHandleReopen(NSApplication.shared, hasVisibleWindows: false)
+        XCTAssertTrue(result)
+    }
+
+    /// Verifies the delegate returns true even when windows are already visible,
+    /// keeping reopen handling consistent regardless of window visibility state.
+    func testApplicationShouldHandleReopenReturnsTrueWithVisibleWindows() {
+        let delegate = ShellraiserAppDelegate()
+        let result = delegate.applicationShouldHandleReopen(NSApplication.shared, hasVisibleWindows: true)
+        XCTAssertTrue(result)
+    }
 }