fix(focus): détecter correctement l'unfocus sur les backends Wayland

Le suivi du focus laissait les injections app-controlled actives lors d'une
perte de focus réelle (fermeture de la fenêtre courante, retour à un bureau
vide). On corrige la détection sur toute la chaîne :

- FocusService: un app_id vide est désormais traité comme un unfocus réel
  (et non un focus transitoire ignoré), ce qui stoppe les injections liées
  à l'application.
- Sway: on ignore les events 'new' (pas un changement de focus) et on relit
  le focus courant sur un event 'title' non focused.
- WlrForeignToplevelBackend: suit _current_handle, le clear sur stop() et
  émet un FocusEvent vide quand le toplevel actuellement focus se ferme.

Tests: test_focus_service + test_focus_watcher (67) OK; lot feature
historique (295) OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

inputremapper/focus/backends/sway.py

@@ -171,10 +171,14 @@ class SwayFocusBackend(FocusBackend):
             return
 
         change = data.get("change")
-        if change not in ("focus", "title", "new"):
+        if change not in ("focus", "title"):
             return
 
-        event = _container_to_event(data.get("container") or {})
+        if change == "title" and not (data.get("container") or {}).get("focused"):
+            event = self.get_current()
+        else:
+            event = _container_to_event(data.get("container") or {})
+
         if event is not None and self._on_focus is not None:
             self._on_focus(event)
 

inputremapper/focus/backends/wlr_foreign_toplevel.py

@@ -69,6 +69,7 @@ class WlrForeignToplevelBackend(FocusBackend):
         # handle -> {"app_id": str, "title": str, "activated": bool}
         self._toplevels: Dict[Any, Dict[str, Any]] = {}
         self._current: Optional[FocusEvent] = None
+        self._current_handle: Optional[Any] = None
 
     @staticmethod
     def is_available() -> bool:
@@ -171,12 +172,20 @@ class WlrForeignToplevelBackend(FocusBackend):
         event = FocusEvent(
             app_id=info["app_id"], title=info["title"], backend=self.name
         )
+        self._current_handle = handle
         self._current = event
         if self._on_focus is not None:
             self._on_focus(event)
 
     def _on_closed(self, handle) -> None:
         self._toplevels.pop(handle, None)
+        if handle != self._current_handle:
+            return
+
+        self._current_handle = None
+        self._current = FocusEvent(app_id="", title="", backend=self.name)
+        if self._on_focus is not None:
+            self._on_focus(self._current)
 
     def _on_readable(self, _fd: int, condition: int) -> bool:
         if condition & (GLib.IO_HUP | GLib.IO_ERR):
@@ -207,4 +216,5 @@ class WlrForeignToplevelBackend(FocusBackend):
         self._manager = None
         self._registry = None
         self._toplevels.clear()
+        self._current_handle = None
         self._current = None