switch hto monorepo structure

quickshell/Common/ModalManager.qml

@@ -0,0 +1,16 @@
+pragma Singleton
+
+import Quickshell
+import QtQuick
+
+Singleton {
+    id: modalManager
+
+    signal closeAllModalsExcept(var excludedModal)
+
+    function openModal(modal) {
+        if (!modal.allowStacking) {
+            closeAllModalsExcept(modal)
+        }
+    }
+}