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/FormContainer.toHtml.test.ts

@@ -39,3 +39,16 @@ describe('FormContainer.toHtml relay wiring', () => {
     expect(mid1).not.toBe(mid2);
   });
 });
+
+describe('FormContainer.toHtml method attribute sanitization', () => {
+  test('malicious method value cannot break out of the attribute; falls back to POST', () => {
+    const { html } = toHtml({ action: '/legacy', method: 'POST"><script>alert(1)</script>' }, '');
+    expect(html).not.toContain('<script');
+    expect(html).toContain('method="POST"');
+  });
+
+  test('legitimate GET method still passes through unchanged (non-relay path)', () => {
+    const { html } = toHtml({ action: '/legacy', method: 'GET' }, '');
+    expect(html).toContain('method="GET"');
+  });
+});