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/layout/Section.toHtml.test.ts

@@ -0,0 +1,75 @@
+import { describe, test, expect } from 'vitest';
+import { Section } from './Section';
+
+const toHtml = (Section as any).toHtml;
+
+describe('Section.toHtml anchorId', () => {
+  test('escapes a malicious anchorId (attribute breakout attempt)', () => {
+    const { html } = toHtml({ anchorId: 'x" onmouseover="alert(1)' }, 'child');
+    expect(html).not.toContain('onmouseover="alert(1)"');
+  });
+
+  test('a normal anchorId still renders correctly', () => {
+    const { html } = toHtml({ anchorId: 'my-section' }, 'child');
+    expect(html).toContain('id="my-section"');
+  });
+});
+
+describe('Section.toHtml childrenHtml passthrough', () => {
+  test('children are preserved', () => {
+    const { html } = toHtml({}, '<p>hello</p>');
+    expect(html).toContain('<p>hello</p>');
+  });
+});
+
+describe('Section.toHtml shape divider color/height XSS hardening', () => {
+  test('a malicious topDividerColor cannot break out of the SVG style attribute', () => {
+    const malicious = 'red" onmouseover="alert(1)';
+    const { html } = toHtml({ topDivider: 'wave', topDividerColor: malicious }, '');
+    expect(html).not.toContain('onmouseover="alert(1)"');
+  });
+
+  test('a malicious topDividerColor cannot inject a </style><script> breakout', () => {
+    const malicious = 'red</style><script>alert(1)</script>';
+    const { html } = toHtml({ topDivider: 'wave', topDividerColor: malicious }, '');
+    expect(html).not.toContain('<script>alert(1)</script>');
+  });
+
+  test('a malicious bottomDividerHeight cannot break out of the wrapper style attribute', () => {
+    const malicious = '50px" onmouseover="alert(1)';
+    const { html } = toHtml({ bottomDivider: 'angle', bottomDividerHeight: malicious }, '');
+    expect(html).not.toContain('onmouseover="alert(1)"');
+  });
+
+  test('a normal divider color/height still renders correctly', () => {
+    const { html } = toHtml({ topDivider: 'wave', topDividerColor: '#123456', topDividerHeight: '80px' }, '');
+    expect(html).toContain('fill:#123456');
+    expect(html).toContain('height:80px');
+  });
+
+  test('divider shape "none" emits no divider markup', () => {
+    const { html } = toHtml({ topDivider: 'none' }, 'child');
+    expect(html).not.toContain('<svg');
+  });
+
+  test('an unrecognized divider shape value emits no divider markup and no injected content', () => {
+    const malicious = 'wave"><script>alert(1)</script>' as any;
+    const { html } = toHtml({ topDivider: malicious }, 'child');
+    expect(html).not.toContain('<script>alert(1)</script>');
+    expect(html).not.toContain('<svg');
+  });
+
+  test('a prototype-property-name divider shape (__proto__) does not leak [object Object]/function source into the SVG path', () => {
+    const { html } = toHtml({ topDivider: '__proto__' as any }, 'child');
+    expect(html).not.toContain('[object');
+    expect(html).not.toContain('native code');
+    expect(html).not.toContain('<svg');
+  });
+
+  test('a prototype-property-name divider shape (toString) does not leak Object.prototype.toString source into the SVG path', () => {
+    const { html } = toHtml({ topDivider: 'toString' as any }, 'child');
+    expect(html).not.toContain('[object');
+    expect(html).not.toContain('native code');
+    expect(html).not.toContain('<svg');
+  });
+});