fix(builder): escape/allowlist all attribute-value sinks incl. numeric/enum props (XSS)

An adversarial pass found 5 Critical XSS sinks where props declared number/enum
in TypeScript were interpolated raw into exported HTML attribute values,
trusting the type — but nothing enforces it at runtime (AI update_props only
validates node_id; deserialized saved state is untyped JSON). Fixed all 5
(NumberCounter data-target, StarRating aria-label, FormContainer method,
ContactForm/InputField input type) plus 6 sibling sinks found by an exhaustive
audit of every attribute-value interpolation across src/components: a
JS-source injection into ContentSlider's inline setInterval script, a
prototype-pollution-adjacent allowlist gap in Section's divider-shape lookup,
TextareaField rows, Testimonials rating aria-label, HeroSimple textAlign, and
MapEmbed zoom. Adds shared sanitizeFormMethod/sanitizeInputType allowlist
helpers to utils/escape.ts alongside the existing escapeAttr/safeUrl/cssValue
primitives. Every fix is TDD'd: a malicious-value test reproduces the raw
injection against the pre-fix code, then passes after the fix.

502 tests green (npx vitest run), tsc + vite build green (npm run build).

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

craft/src/components/forms/TextareaField.toHtml.test.ts

@@ -50,3 +50,16 @@ describe('TextareaField.toHtml deterministic + unique ids (thread node id, resol
     expect(id1).toBe(id2);
   });
 });
+
+describe('TextareaField.toHtml rows attribute sanitization', () => {
+  test('malicious rows value cannot break out of the attribute; falls back to a numeric rows', () => {
+    const { html } = toHtml({ label: 'Message', name: 'message', rows: '4"><script>alert(1)</script>' as any }, '');
+    expect(html).not.toContain('<script');
+    expect(html).toMatch(/rows="\d+"/);
+  });
+
+  test('legitimate numeric rows still passes through unchanged', () => {
+    const { html } = toHtml({ label: 'Message', name: 'message', rows: 8 }, '');
+    expect(html).toContain('rows="8"');
+  });
+});