Deplace l'overlay Cocoa derriere le contrat Overlay, sans le modifier

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app.py

@@ -30,7 +30,7 @@ from pynput import keyboard
 
 from controller import ZonzaController
 from core import CONFIG, validate_config
-from pulse_window import PulseWindow
+from interface import classe_overlay_pour
 from systeme import choisir_systeme
 
 _STATE_TITLES = {
@@ -49,7 +49,7 @@ class ZonzaApp(NSObject):
             return None
         self._item = None
         self._sounds_item = None
-        self.pulse = PulseWindow.alloc().init()
+        self.pulse = classe_overlay_pour().alloc().init()
         self.controller = ZonzaController(
             CONFIG, self.pulse, on_state=self._set_state,
             run_on_main=AppHelper.callAfter,