feat(site-builder): tokenise colours hard-coded inside components

Component render/toHtml now use var(--wsb-*) instead of hex so Site Design
palette changes reach FeaturesGrid, Testimonials, Accordion, PricingTable,
CTA/CallToAction, forms, Gallery, Tabs and others. Exemption lists removed.

Refs #44

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

craft/src/components/forms/SubscribeForm.tsx

@@ -82,9 +82,9 @@ export const SubscribeForm: UserComponent<SubscribeFormProps> = ({
             padding: '12px 16px',
             fontSize: '15px',
             fontFamily: 'Inter, sans-serif',
-            border: '1px solid #d1d5db',
+            border: `1px solid ${tokenRef('border')}`,
             borderRadius: isInline ? '8px 0 0 8px' : '8px',
-            backgroundColor: '#ffffff',
+            backgroundColor: tokenRef('bg'),
             color: tokenRef('text'),
             outline: 'none',
             boxSizing: 'border-box',
@@ -97,7 +97,7 @@ export const SubscribeForm: UserComponent<SubscribeFormProps> = ({
             fontSize: '15px',
             fontWeight: '600',
             fontFamily: 'Inter, sans-serif',
-            color: '#ffffff',
+            color: tokenRef('bg'),
             backgroundColor: buttonColor,
             border: 'none',
             borderRadius: isInline ? '0 8px 8px 0' : '8px',
@@ -122,7 +122,7 @@ SubscribeForm.craft = {
     buttonText: 'Subscribe',
     buttonColor: tokenRef('primary'),
     layout: 'inline',
-    style: { backgroundColor: '#f8fafc' },
+    style: { backgroundColor: tokenRef('bg') },
     recipientEmail: '',
     thankYouUrl: '',
     animation: '',
@@ -171,14 +171,14 @@ SubscribeForm.craft = {
     alignItems: 'stretch',
   });
 
-  const inputStyleStr = `flex:1;padding:12px 16px;font-size:15px;font-family:Inter,sans-serif;border:1px solid #d1d5db;border-radius:${isInline ? '8px 0 0 8px' : '8px'};background-color:#ffffff;color:${tokenRef('text')};outline:none;box-sizing:border-box`;
+  const inputStyleStr = `flex:1;padding:12px 16px;font-size:15px;font-family:Inter,sans-serif;border:1px solid ${tokenRef('border')};border-radius:${isInline ? '8px 0 0 8px' : '8px'};background-color:${tokenRef('bg')};color:${tokenRef('text')};outline:none;box-sizing:border-box`;
 
   const btnStyle = cssPropsToString({
     padding: '12px 24px',
     fontSize: '15px',
     fontWeight: '600',
     fontFamily: 'Inter, sans-serif',
-    color: '#ffffff',
+    color: tokenRef('bg'),
     backgroundColor: buttonColor,
     border: 'none',
     borderRadius: isInline ? '0 8px 8px 0' : '8px',