feat(window_manager): add get_display_topology_signature for dynamic monitor and resolution change detection

catser/window_manager.py

@@ -349,6 +349,16 @@ class WindowManager:
         user32.EnumDisplayMonitors(0, None, MONITORENUMPROC(enum_mon_proc), 0)
         return monitors
 
+    @classmethod
+    def get_display_topology_signature(cls) -> tuple:
+        """
+        Returns a hashable signature representing current displays, resolutions, and work areas.
+        Used to detect dynamic monitor connection, disconnection, or resolution adjustments.
+        """
+        monitors = cls.get_monitors()
+        vd = cls.get_virtual_desktop_bounds()
+        return (vd, tuple((m.handle, m.is_primary, m.rect, m.work_area) for m in monitors))
+
     @classmethod
     def get_floor_y_at(cls, x: float, cat_height: int) -> float:
         """