test(builder): cover useVisualViewport; fix: disable Select-Parent at ROOT in desktop context menu

- useVisualViewport.test.tsx: covers the visualViewport-undefined fallback,
  the keyboardInset math on a mocked visualViewport resize, and
  listener add/remove (resize + scroll) across mount/unmount.
- ContextMenu.tsx: Select Parent was only disabled at isRoot, so selecting
  a top-level section and choosing Select Parent silently landed on the
  un-editable ROOT (no outline, no toolbar) -- a dead end. Switched the
  guard to useNodeActions' canSelectParent (false whenever the node's
  parent is ROOT or missing), matching the mobile selection toolbar's
  existing identical guard.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

craft/src/hooks/useVisualViewport.test.tsx

@@ -0,0 +1,146 @@
+import { describe, test, expect, vi, beforeEach, afterEach } from 'vitest';
+import React from 'react';
+import { createRoot, Root } from 'react-dom/client';
+import { act } from 'react-dom/test-utils';
+import { useVisualViewportInsets } from './useVisualViewport';
+
+/**
+ * Fast-follow coverage for `useVisualViewportInsets` (BottomSheet's
+ * keyboard-avoidance source of truth). Mirrors the bare createRoot + act
+ * harness `useIsMobile.test.tsx` uses (no @testing-library/react in this
+ * repo). Covers:
+ *  - the no-`visualViewport` fallback (older WebViews) returns
+ *    `{ height: window.innerHeight, keyboardInset: 0 }` AND registers no
+ *    listener (there's nothing to listen to).
+ *  - the keyboard-open math: `keyboardInset = innerHeight - (vv.height +
+ *    vv.offsetTop)`, recomputed when the mocked vv fires `resize`.
+ *  - both `resize` and `scroll` listeners are added on mount and the SAME
+ *    handler is removed for both on unmount (a leaked listener would keep
+ *    reacting after the owning component -- e.g. BottomSheet -- is gone).
+ */
+
+let container: HTMLDivElement;
+let root: Root;
+let originalInnerHeight: number;
+let originalVisualViewport: VisualViewport | null;
+
+function render(ui: React.ReactElement) {
+  container = document.createElement('div');
+  document.body.appendChild(container);
+  act(() => {
+    root = createRoot(container);
+    root.render(ui);
+  });
+}
+
+function unmount() {
+  act(() => {
+    root.unmount();
+  });
+  container.remove();
+}
+
+/** A minimal fake `visualViewport`: just enough surface for the hook
+ *  (`height`, `offsetTop`, `addEventListener`/`removeEventListener`). */
+function makeVisualViewport(height: number, offsetTop: number) {
+  const listeners: Record<string, Array<() => void>> = { resize: [], scroll: [] };
+  const vv: any = {
+    height,
+    offsetTop,
+    addEventListener: vi.fn((type: string, fn: () => void) => {
+      listeners[type].push(fn);
+    }),
+    removeEventListener: vi.fn((type: string, fn: () => void) => {
+      const i = listeners[type].indexOf(fn);
+      if (i !== -1) listeners[type].splice(i, 1);
+    }),
+  };
+  return {
+    vv,
+    fire: (type: 'resize' | 'scroll') => listeners[type].forEach((fn) => fn()),
+    listenerCount: (type: 'resize' | 'scroll') => listeners[type].length,
+  };
+}
+
+let probed: { height: number; keyboardInset: number } | null = null;
+const Probe: React.FC = () => {
+  probed = useVisualViewportInsets();
+  return <span data-height={probed.height} data-inset={probed.keyboardInset} />;
+};
+
+beforeEach(() => {
+  originalInnerHeight = window.innerHeight;
+  originalVisualViewport = window.visualViewport;
+  probed = null;
+});
+
+afterEach(() => {
+  Object.defineProperty(window, 'innerHeight', {
+    value: originalInnerHeight,
+    configurable: true,
+    writable: true,
+  });
+  Object.defineProperty(window, 'visualViewport', {
+    value: originalVisualViewport,
+    configurable: true,
+  });
+});
+
+describe('useVisualViewportInsets', () => {
+  test('falls back to innerHeight/0 and registers no listener when visualViewport is undefined', () => {
+    Object.defineProperty(window, 'innerHeight', { value: 800, configurable: true, writable: true });
+    Object.defineProperty(window, 'visualViewport', { value: undefined, configurable: true });
+
+    render(<Probe />);
+
+    expect(probed).toEqual({ height: 800, keyboardInset: 0 });
+
+    unmount();
+  });
+
+  test('computes keyboardInset from visualViewport and recomputes on resize', () => {
+    Object.defineProperty(window, 'innerHeight', { value: 800, configurable: true, writable: true });
+    const { vv, fire } = makeVisualViewport(800, 0);
+    Object.defineProperty(window, 'visualViewport', { value: vv, configurable: true });
+
+    render(<Probe />);
+
+    // No keyboard open: vv fills the layout viewport exactly.
+    expect(probed).toEqual({ height: 800, keyboardInset: 0 });
+
+    // Simulate the on-screen keyboard opening: the visual viewport shrinks.
+    vv.height = 500;
+    vv.offsetTop = 0;
+    act(() => {
+      fire('resize');
+    });
+
+    expect(probed).toEqual({ height: 500, keyboardInset: 300 });
+
+    unmount();
+  });
+
+  test('registers resize and scroll listeners on mount and removes both (same handler) on unmount', () => {
+    Object.defineProperty(window, 'innerHeight', { value: 800, configurable: true, writable: true });
+    const { vv, listenerCount } = makeVisualViewport(800, 0);
+    Object.defineProperty(window, 'visualViewport', { value: vv, configurable: true });
+
+    render(<Probe />);
+
+    expect(vv.addEventListener).toHaveBeenCalledWith('resize', expect.any(Function));
+    expect(vv.addEventListener).toHaveBeenCalledWith('scroll', expect.any(Function));
+    expect(listenerCount('resize')).toBe(1);
+    expect(listenerCount('scroll')).toBe(1);
+
+    const resizeHandler = vv.addEventListener.mock.calls.find((c: any[]) => c[0] === 'resize')[1];
+    const scrollHandler = vv.addEventListener.mock.calls.find((c: any[]) => c[0] === 'scroll')[1];
+    expect(resizeHandler).toBe(scrollHandler);
+
+    unmount();
+
+    expect(vv.removeEventListener).toHaveBeenCalledWith('resize', resizeHandler);
+    expect(vv.removeEventListener).toHaveBeenCalledWith('scroll', scrollHandler);
+    expect(listenerCount('resize')).toBe(0);
+    expect(listenerCount('scroll')).toBe(0);
+  });
+});

craft/src/panels/context-menu/ContextMenu.tsx

@@ -195,7 +195,12 @@ export const ContextMenu: React.FC<ContextMenuProps> = ({
       label: 'Select Parent',
       icon: 'level-up',
       action: selectParent,
-      disabled: isRoot,
+      // Not just `isRoot`: the real dead-end is when nodeId's PARENT is
+      // ROOT (selecting a top-level section -> Select Parent would only
+      // select the page-wide, un-editable ROOT -- no outline, no toolbar).
+      // `canSelectParent` (useNodeActions) already encodes that and matches
+      // the mobile selection toolbar's identical guard.
+      disabled: !nodeActions.canSelectParent,
       dividerAfter: true,
     },
     {