refactor(litegraph): add widget filtering helper methods

- Add getLayoutWidgets() to LGraphNode for layout calculations
- Add hasAdvancedWidgets() to LGraphNode for advanced widget checks
- Update _arrangeWidgets() to use getLayoutWidgets()
- Update toggleAdvanced() and context menu to use hasAdvancedWidgets()

Part of Phase 2 WidgetValueStore expansion (Step 5).

Amp-Thread-ID: https://ampcode.com/threads/T-019c263e-978e-7324-b320-57e15bf6065c
Co-authored-by: Amp <amp@ampcode.com>

src/lib/litegraph/src/LGraphCanvas.ts

@@ -8221,7 +8221,7 @@ export class LGraphCanvas implements CustomEventDispatcher<LGraphCanvasEventMap>
           callback: LGraphCanvas.onMenuNodeCollapse
         })
       }
-      if (node.widgets?.some((w) => w.advanced)) {
+      if (node.hasAdvancedWidgets()) {
         options.push({
           content: node.showAdvanced ? 'Hide Advanced' : 'Show Advanced',
           callback: LGraphCanvas.onMenuToggleAdvanced

src/lib/litegraph/src/LGraphNode.ts

@@ -3511,7 +3511,7 @@ export class LGraphNode
    * Toggles advanced mode of the node, showing advanced widgets
    */
   toggleAdvanced() {
-    if (!this.widgets?.some((w) => w.advanced)) return
+    if (!this.hasAdvancedWidgets()) return
     if (!this.graph) throw new NullGraphError()
     this.graph._version++
     this.showAdvanced = !this.showAdvanced
@@ -3889,6 +3889,21 @@ export class LGraphNode
     return !isHidden
   }
 
+  /**
+   * Returns all widgets that should participate in layout calculations.
+   * Filters out hidden widgets only (not collapsed/advanced).
+   */
+  getLayoutWidgets(): IBaseWidget[] {
+    return this.widgets?.filter((w) => !w.hidden) ?? []
+  }
+
+  /**
+   * Returns `true` if the node has any advanced widgets.
+   */
+  hasAdvancedWidgets(): boolean {
+    return this.widgets?.some((w) => w.advanced) ?? false
+  }
+
   updateComputedDisabled() {
     if (!this.widgets) return
     for (const widget of this.widgets)
@@ -4099,7 +4114,7 @@ export class LGraphNode
       w: IBaseWidget
     }[] = []
 
-    const visibleWidgets = this.widgets.filter((w) => !w.hidden)
+    const visibleWidgets = this.getLayoutWidgets()
 
     for (const w of visibleWidgets) {
       if (w.computeSize) {