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/HtmlBlock.toHtml.test.ts

@@ -10,4 +10,16 @@ describe('HtmlBlock.toHtml sanitizes raw code (A4.1)', () => {
     expect(html).not.toContain('onclick');
     expect(html).toContain('<p>hi</p>');
   });
+
+  test('does not wrap output in an unsanitized element carrying the style prop raw', () => {
+    // toHtml only ever returns the sanitized `code` blob -- there is no
+    // wrapper <div style="..."> in the exported HTML, so a malicious
+    // `style` prop (e.g. an attacker-controlled object with a breakout
+    // toString()) has nothing to splice into.
+    const malicious = { toString: () => 'color:red" onmouseover="alert(1)' } as any;
+    const { html } = toHtml({ code: '<p>hi</p>', style: malicious }, '');
+    expect(html).not.toMatch(/onmouseover/);
+    expect(html).not.toMatch(/<div/);
+    expect(html).toBe('<p>hi</p>');
+  });
 });