feat(builder): mobile-B touch editing -- selection toolbar, tap-to-add, swipe-dismiss

Phase B makes the Craft.js editor genuinely usable by touch on top of Phase
A's responsive shell, gated entirely behind useIsMobile()/<=768px:

- Extract useNodeActions(nodeId) out of ContextMenu.tsx (move/duplicate/
  delete/select-parent), shared by the desktop right-click menu (behavior
  unchanged) and the new mobile MobileSelectionToolbar.
- MobileSelectionToolbar: bottom-fixed selection toolbar (Move Up/Down,
  Duplicate, Select Parent, Edit Styles, two-tap Delete confirm), hidden
  while a sheet is open.
- BlocksPanel: tap-to-add on mobile (insert after selection, close sheet,
  select + scroll the new node into view); desktop drag/double-click
  unchanged.
- LayersPanel rows >=44px on mobile; HeadCodeModal portaled to document.body
  (same fix TemplateModal already had); BottomSheet gets swipe-to-dismiss
  and on-screen-keyboard clearance via a new useVisualViewportInsets hook.

Also fixes two pre-existing bugs surfaced only by driving a real Craft.js
document with Playwright touch input (masked by tests that mock
@craftjs/core): regenerateTreeIds structuredClone'd a live node's whole
data object, including the component function reference in data.type,
throwing DataCloneError and silently breaking Duplicate/Paste for every
node type; and an earlier useNodeActions draft cached canMoveUp/canMoveDown
inside a useEditor collector closed over nodeId, which goes stale for one
render whenever the selection changes without an unrelated store event.

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

craft/src/utils/craft-tree.test.ts

@@ -147,6 +147,37 @@ describe('regenerateTreeIds', () => {
 
     expect(input.nodes['root-1'].data.props).toEqual({ alignment: 'left' });
   });
+
+  // Regression test (found via real-browser Playwright touch verification,
+  // Phase B): a LIVE Craft.js node's `data.type` is the actual component
+  // function reference (not the `{resolvedName}` string wrapper used only
+  // in SERIALIZED state) -- `query.node(id).toNodeTree()` returns nodes
+  // shaped exactly like this. The previous implementation ran
+  // `structuredClone(oldNode.data)` on the WHOLE data object, which throws
+  // `DataCloneError` the instant `data.type` is a function, silently
+  // breaking Duplicate (ContextMenu.tsx / useNodeActions.ts) and Ctrl+V
+  // Paste (useKeyboardShortcuts.ts) for every real node in the app --
+  // masked by every other test in this suite using a plain string `type`
+  // ('div'), and by unit tests elsewhere that mock `@craftjs/core` entirely
+  // (so `toNodeTree()` never actually returns a function there).
+  test('does not throw when data.type is a live component function reference', () => {
+    const ButtonLikeComponent = (props: { text?: string }) => props.text;
+    const input = makeTree();
+    input.nodes['root-1'].data.type = ButtonLikeComponent as unknown as Node['data']['type'];
+    input.nodes['root-1'].data.props = { text: 'Click Me' };
+
+    expect(() => regenerateTreeIds(input)).not.toThrow();
+
+    const output = regenerateTreeIds(input);
+    const outputRoot = output.nodes[output.rootNodeId];
+    // The component reference itself is preserved (shared, not cloned --
+    // it's a stable reference, not mutable data).
+    expect(outputRoot.data.type).toBe(ButtonLikeComponent);
+    // Props are still genuinely deep-cloned (the actual bug fix's point).
+    expect(outputRoot.data.props).toEqual({ text: 'Click Me' });
+    (outputRoot.data.props as { text: string }).text = 'changed';
+    expect(input.nodes['root-1'].data.props).toEqual({ text: 'Click Me' });
+  });
 });
 
 describe('flattenTreeForCraft', () => {