Fix ComfyUI shortcut leaks in LayerForge

Technical details:
- skip LayerForge canvas and panel shortcuts when focus is inside editable controls
- patch ComfyUI ChangeTracker undoRedo so Ctrl/Cmd+Z does not leak to graph history while LayerForge owns the shortcut context
- stop clipboard copy/cut/paste events from editable LayerForge UI from bubbling into ComfyUI node clipboard handlers
- route widget-root Ctrl/Cmd+Z, Ctrl/Cmd+Y, and Ctrl/Cmd+Shift+Z through LayerForge canvas undo and redo when the widget is active

js/CanvasLayersPanel.js

@@ -118,7 +118,19 @@ export class CanvasLayersPanel {
         this.setupControlButtons();
         this.setupMasterVisibilityToggle();
         // Dodaj listener dla klawiatury, aby usuwanie działało z panelu
+        const isEditableTarget = (target) => {
+            if (!(target instanceof HTMLElement)) {
+                return false;
+            }
+            if (target.isContentEditable) {
+                return true;
+            }
+            return !!target.closest('input, textarea, select, [contenteditable="true"]');
+        };
         this.container.addEventListener('keydown', (e) => {
+            if (isEditableTarget(e.target)) {
+                return;
+            }
             if (e.key === 'Delete' || e.key === 'Backspace') {
                 e.preventDefault();
                 e.stopPropagation();