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/ButtonLink.toHtml.test.ts

@@ -0,0 +1,54 @@
+import { describe, test, expect } from 'vitest';
+import { ButtonLink } from './ButtonLink';
+
+const toHtml = (ButtonLink as any).toHtml;
+
+describe('ButtonLink.toHtml href sanitization (attacker-controlled `href` prop)', () => {
+  test('a javascript: URL is neutralized', () => {
+    const { html } = toHtml({ href: 'javascript:alert(1)', text: 'Click' }, '');
+    expect(html).not.toContain('javascript:alert');
+  });
+
+  test('a quote-breakout href does not escape the href attribute', () => {
+    const malicious = '"><script>alert(1)</script>';
+    const { html } = toHtml({ href: malicious, text: 'Click' }, '');
+    expect(html).not.toContain('<script>alert(1)</script>');
+  });
+
+  test('a normal href still renders correctly', () => {
+    const { html } = toHtml({ href: 'https://example.com', text: 'Click' }, '');
+    expect(html).toContain('href="https://example.com"');
+  });
+});
+
+describe('ButtonLink.toHtml target (boolean-gated, not raw interpolation)', () => {
+  test('an attribute-breakout value for target does not reach the output raw', () => {
+    const malicious = '_blank" onmouseover="alert(1)' as any;
+    const { html } = toHtml({ href: '#', text: 'x', target: malicious }, '');
+    expect(html).not.toContain('onmouseover');
+  });
+
+  test('target="_blank" still adds rel=noopener noreferrer', () => {
+    const { html } = toHtml({ href: '#', text: 'x', target: '_blank' }, '');
+    expect(html).toContain('target="_blank"');
+    expect(html).toContain('rel="noopener noreferrer"');
+  });
+});
+
+describe('ButtonLink.toHtml text escaping (attacker-controlled `text` prop)', () => {
+  test('a tag-breakout attempt in text is neutralized (no injected element)', () => {
+    const { html } = toHtml({ href: '#', text: '</a><img src=x onerror=alert(1)>' }, '');
+    expect(html).not.toContain('<img');
+    expect(html).toContain('&lt;img');
+  });
+
+  test('ampersand is escaped for well-formed text content (consistency with escapeHtml)', () => {
+    const { html } = toHtml({ href: '#', text: 'Tom & Jerry' }, '');
+    expect(html).toContain('Tom &amp; Jerry');
+  });
+
+  test('a normal text value still renders unchanged', () => {
+    const { html } = toHtml({ href: '#', text: 'Click Me' }, '');
+    expect(html).toContain('>Click Me</a>');
+  });
+});