Mark event monitor properties as nonisolated(unsafe)

The event monitor properties need to be accessible from nonisolated
stop methods that are called from deinit. Marking them as
nonisolated(unsafe) is safe because:
- They are opaque tokens from NSEvent.addMonitorForEvents
- NSEvent.removeMonitor is thread-safe
- We only read them to pass to removeMonitor

This resolves the MainActor isolation compilation errors.

Author: claude

Sources/ClickIt/Lite/SimpleHotkeyManager.swift

@@ -15,12 +15,12 @@ final class SimpleHotkeyManager {
 
     // MARK: - Properties
 
-    private var globalMonitor: Any?
-    private var localMonitor: Any?
+    nonisolated(unsafe) private var globalMonitor: Any?
+    nonisolated(unsafe) private var localMonitor: Any?
     private var onEmergencyStop: (() -> Void)?
 
-    private var globalMouseMonitor: Any?
-    private var localMouseMonitor: Any?
+    nonisolated(unsafe) private var globalMouseMonitor: Any?
+    nonisolated(unsafe) private var localMouseMonitor: Any?
     private var onRightMouseClick: (() -> Void)?
     private var lastClickTime: TimeInterval = 0
     private let clickDebounceInterval: TimeInterval = 0.1