Fix notification observer concurrency issues

- Use queue: .main for notification observers to ensure MainActor execution
- Add @mainactor to CarbonKeyboardShortcuts.register method
- Add @mainactor to handleOnKeyDown/Up methods
- Remove unnecessary MainActor.assumeIsolated blocks

Author: steipete

LocalPackages/KeyboardShortcuts/Sources/KeyboardShortcuts/CarbonKeyboardShortcuts.swift

@@ -134,6 +134,7 @@ enum CarbonKeyboardShortcuts {
 		}
 	}
 
+	@MainActor
 	static func register(
 		_ shortcut: KeyboardShortcuts.Shortcut,
 		onKeyDown: @escaping (KeyboardShortcuts.Shortcut) -> Void,

LocalPackages/KeyboardShortcuts/Sources/KeyboardShortcuts/KeyboardShortcuts.swift

@@ -398,6 +398,7 @@ public enum KeyboardShortcuts {
 		return decoded
 	}
 
+	@MainActor
 	private static func handleOnKeyDown(_ shortcut: Shortcut) {
 		guard !isPaused else {
 			return
@@ -424,6 +425,7 @@ public enum KeyboardShortcuts {
 		}
 	}
 
+	@MainActor
 	private static func handleOnKeyUp(_ shortcut: Shortcut) {
 		guard !isPaused else {
 			return

LocalPackages/KeyboardShortcuts/Sources/KeyboardShortcuts/RecorderCocoa.swift

@@ -120,18 +120,16 @@ extension KeyboardShortcuts {
 		}
 
 		private func setUpEvents() {
-			shortcutsNameChangeObserver = NotificationCenter.default.addObserver(forName: .shortcutByNameDidChange, object: nil, queue: nil) { [weak self] notification in
-				MainActor.assumeIsolated { [weak self] in
-					guard
-						let self,
-						let nameInNotification = notification.userInfo?["name"] as? KeyboardShortcuts.Name,
-						nameInNotification == self.shortcutName
-					else {
-						return
-					}
-
-					self.setStringValue(name: nameInNotification)
+			shortcutsNameChangeObserver = NotificationCenter.default.addObserver(forName: .shortcutByNameDidChange, object: nil, queue: .main) { [weak self] notification in
+				guard
+					let self,
+					let nameInNotification = notification.userInfo?["name"] as? KeyboardShortcuts.Name,
+					nameInNotification == self.shortcutName
+				else {
+					return
 				}
+
+				self.setStringValue(name: nameInNotification)
 			}
 		}
 
@@ -183,25 +181,21 @@ extension KeyboardShortcuts {
 
 			// Ensures the recorder stops when the window is hidden.
 			// This is especially important for Settings windows, which as of macOS 13.5, only hides instead of closes when you click the close button.
-			windowDidResignKeyObserver = NotificationCenter.default.addObserver(forName: NSWindow.didResignKeyNotification, object: window, queue: nil) { [weak self] _ in
-				MainActor.assumeIsolated { [weak self] in
-					guard
-						let self,
-						let window = self.window
-					else {
-						return
-					}
-
-					self.endRecording()
-					window.makeFirstResponder(nil)
+			windowDidResignKeyObserver = NotificationCenter.default.addObserver(forName: NSWindow.didResignKeyNotification, object: window, queue: .main) { [weak self] _ in
+				guard
+					let self,
+					let window = self.window
+				else {
+					return
 				}
+
+				self.endRecording()
+				window.makeFirstResponder(nil)
 			}
 
 			// Ensures the recorder does not receive initial focus when a hidden window becomes unhidden.
-			windowDidBecomeKeyObserver = NotificationCenter.default.addObserver(forName: NSWindow.didBecomeKeyNotification, object: window, queue: nil) { [weak self] _ in
-				MainActor.assumeIsolated {
-					self?.preventBecomingKey()
-				}
+			windowDidBecomeKeyObserver = NotificationCenter.default.addObserver(forName: NSWindow.didBecomeKeyNotification, object: window, queue: .main) { [weak self] _ in
+				self?.preventBecomingKey()
 			}
 
 			preventBecomingKey()