Protect live state during restore and reset

config/dot/quickshell/services/Displays.qml

@@ -41,6 +41,7 @@ Singleton {
     property bool revertVerificationActive: false
     property int operationGeneration: 0
     property int revertGeneration: -1
+    property bool externalChangeBlocked: false
     property int secondsLeft: 0
 
     readonly property bool awaitingConfirmation: root.pendingOutput !== ""
@@ -271,6 +272,10 @@ Singleton {
     // Applies immediately and starts the countdown. Nothing is stored yet: the
     // settings file is only written by confirm().
     function apply(output: string, mode: string, scale: real, transform: int): bool {
+        if (root.externalChangeBlocked) {
+            root.lastError = "Wait for Settings to finish restoring before changing a display.";
+            return false;
+        }
         if (root.busy) {
             root.lastError = "Wait for the current display operation to finish.";
             return false;