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/Heading.tsx

@@ -1,6 +1,7 @@
 import React, { CSSProperties, useCallback, useRef, useEffect } from 'react';
 import { useNode, UserComponent } from '@craftjs/core';
 import { cssPropsToString } from '../../utils/style-helpers';
+import { escapeHtml } from '../../utils/escape';
 
 type HeadingLevel = 'h1' | 'h2' | 'h3' | 'h4' | 'h5' | 'h6';
 
@@ -110,7 +111,7 @@ Heading.craft = {
 
 (Heading as any).toHtml = (props: HeadingProps, _childrenHtml: string) => {
   const tag = sanitizeHeadingLevel(props.level);
-  const safeText = (props.text || '').replace(/</g, '&lt;').replace(/>/g, '&gt;');
+  const safeText = escapeHtml(props.text || '');
   const styleStr = cssPropsToString(props.style);
   return { html: `<${tag}${styleStr ? ` style="${styleStr}"` : ''}>${safeText}</${tag}>` };
 };