site-builder: surface Spotify/Twitch + contact-form recipient in the Styles (guided) panel

The right panel only renders GuidedStyles (there is no Settings tab), so the
per-component Settings panels I'd edited never showed. Add Spotify/Twitch to
SocialStylePanel's platform dropdown and the 'Send submissions to' + thank-you
fields to FormStylePanel (shown for any form with a recipientEmail prop).

craft/src/panels/right/styles/FormStylePanel.tsx

@@ -35,6 +35,24 @@ export const FormStylePanel: React.FC<StylePanelProps> = ({ selectedId, nodeProp
 
   return (
     <>
+      {/* Contact-form relay: where submissions are emailed. Present on ContactForm
+          and FormContainer (both have recipientEmail/thankYouUrl props). */}
+      {nodeProps.recipientEmail !== undefined && (
+        <div style={sectionGap}>
+          <label style={labelStyle}>Send submissions to (email)</label>
+          <input type="email" value={nodeProps.recipientEmail || ''} onChange={(e) => setProp('recipientEmail', e.target.value)} placeholder="you@example.com" style={inputStyle} />
+          <p style={{ fontSize: 10, color: '#71717a', margin: '4px 0 0' }}>
+            Emailed via the site's contact-form relay (an admin must enable it in Server Settings). Leave blank to use the Form Action URL instead.
+          </p>
+        </div>
+      )}
+      {nodeProps.thankYouUrl !== undefined && (
+        <div style={sectionGap}>
+          <label style={labelStyle}>Thank-you page URL (optional)</label>
+          <input type="text" value={nodeProps.thankYouUrl || ''} onChange={(e) => setProp('thankYouUrl', e.target.value)} placeholder="/thank-you (blank = hosted page)" style={inputStyle} />
+        </div>
+      )}
+
       {/* Form action/method */}
       {nodeProps.action !== undefined && (
         <div style={sectionGap}>