feat: add system sound alert module

Made-with: Cursor

src/cursor_flasher/sound.py

@@ -0,0 +1,17 @@
+"""System sound playback."""
+from Cocoa import NSSound
+
+from cursor_flasher.config import Config
+
+
+def play_alert(config: Config) -> None:
+    """Play the configured alert sound if enabled."""
+    if not config.sound_enabled:
+        return
+
+    sound = NSSound.soundNamed_(config.sound_name)
+    if sound is None:
+        return
+
+    sound.setVolume_(config.sound_volume)
+    sound.play()