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/basic/SearchBar.toHtml.test.ts

@@ -11,3 +11,22 @@ describe('SearchBar.toHtml decorative icons (F2.5)', () => {
     icons.forEach((tag: string) => expect(tag).toContain('aria-hidden="true"'));
   });
 });
+
+describe('SearchBar.toHtml XSS hardening (placeholder/buttonText/showButton)', () => {
+  test('a placeholder value with an attribute-breakout string cannot escape placeholder=""', () => {
+    const malicious = 'Search..." onmouseover="alert(1)';
+    const { html } = toHtml({ placeholder: malicious }, '');
+    expect(html).not.toMatch(/"\s+onmouseover="/);
+  });
+
+  test('a buttonText value with a script tag is escaped as text content, not raw HTML', () => {
+    const malicious = '<script>alert(1)</script>';
+    const { html } = toHtml({ buttonText: malicious, showButton: true }, '');
+    expect(html).not.toContain('<script>alert(1)</script>');
+  });
+
+  test('a non-boolean showButton (string "false") still yields fixed, safe border-radius values', () => {
+    const { html } = toHtml({ showButton: 'false' as any }, '');
+    expect(html).toMatch(/border-radius:(8px 0 0 8px|8px)/);
+  });
+});