deterministic + unique ids in 6 components (node-derived scope)

Migrates Menu, ColumnLayout, Countdown, Gallery, Tabs, InputField, and
TextareaField from Math.random()/content-hash scope ids to the threaded
Craft node id (via scopeId()), keeping every emitted element id,
aria-controls/aria-labelledby/for, and inline <script> function
name/getElementById() call consistently scoped per component.

Resolves the two Important id-collision review findings:
- Tabs: tabId was djb2(anchorId||labels) -- two default Tabs instances
  produced identical aria-controls/aria-labelledby ids, so one instance's
  arrow-key script clobbered the other's tab/panel wiring.
- InputField/TextareaField: fieldId was `field-${name}` -- two fields
  sharing a (often default) name produced duplicate <label for>/<input
  id> pairs, breaking the for/id association for one of them.

Also eliminates the remaining Math.random() scope ids in Menu (hover CSS
class scope) and ColumnLayout (nth-child width CSS class scope), so no
export component is non-deterministic anymore.

All fall back to a stable content hash (never Math.random) for legacy
2-arg toHtml() call sites without a node id.

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

craft/src/components/layout/ColumnLayout.toHtml.test.ts

@@ -29,3 +29,33 @@ describe('ColumnLayout.toHtml width export from split', () => {
     expect(html).toContain('<div>A</div><div>B</div>');
   });
 });
+
+describe('ColumnLayout.toHtml deterministic + unique scope ids (thread node id, no Math.random)', () => {
+  const props = { columns: 2, split: '50-50', gap: '16px' };
+
+  test('same node id -> identical output across calls (deterministic)', () => {
+    const { html: html1 } = toHtml(props, '', 'node-col1');
+    const { html: html2 } = toHtml(props, '', 'node-col1');
+    expect(html1).toBe(html2);
+  });
+
+  test('different node ids -> different, non-colliding scope classes (identical columns/split/gap, no collision)', () => {
+    const { html: html1 } = toHtml(props, '', 'node-col1');
+    const { html: html2 } = toHtml(props, '', 'node-col2');
+    const cls1 = html1.match(/class="([^"]+)"/)![1];
+    const cls2 = html2.match(/class="([^"]+)"/)![1];
+    expect(cls1).not.toBe(cls2);
+  });
+
+  test('the <style> nth-child rule and the div class= use the SAME scope', () => {
+    const { html } = toHtml(props, '', 'node-col1');
+    const cls = html.match(/class="([^"]+)"/)![1];
+    expect(html).toContain(`.${cls} > :nth-child(1)`);
+  });
+
+  test('no nodeId (legacy 2-arg call): still deterministic across repeated calls, not random', () => {
+    const { html: html1 } = toHtml(props, '<div>A</div><div>B</div>');
+    const { html: html2 } = toHtml(props, '<div>A</div><div>B</div>');
+    expect(html1).toBe(html2);
+  });
+});