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/sections/Testimonials.toHtml.test.ts

@@ -46,3 +46,28 @@ describe('Testimonials.toHtml decorative star icons (F2.5)', () => {
     stars.forEach((tag: string) => expect(tag).toContain('aria-hidden="true"'));
   });
 });
+
+describe('Testimonials.toHtml rating aria-label sink (attacker-controlled `rating`, typed number but unchecked)', () => {
+  test('malicious rating value cannot break out of the star row aria-label attribute', () => {
+    const malicious = [
+      { quote: 'Q', name: 'N', title: 'T', rating: '5"><script>alert(1)</script>' as any },
+    ];
+    const { html } = toHtml({ testimonials: malicious, layout: 'grid' }, '');
+    expect(html).not.toContain('<script>alert(1)</script>');
+    expect(html).not.toContain('5"><script>');
+  });
+
+  test('non-numeric rating falls back to a safe numeric value', () => {
+    const malicious = [
+      { quote: 'Q', name: 'N', title: 'T', rating: 'not-a-number' as any },
+    ];
+    const { html } = toHtml({ testimonials: malicious, layout: 'grid' }, '');
+    expect(html).toMatch(/aria-label="Rating: 0 out of 5"/);
+  });
+
+  test('normal numeric rating still renders correctly', () => {
+    const { html } = toHtml({ testimonials, layout: 'grid' }, '');
+    expect(html).toContain('aria-label="Rating: 5 out of 5"');
+    expect(html).toContain('aria-label="Rating: 4 out of 5"');
+  });
+});