Add website favicon API and manual favicon profile updates.

Expose GET /tenants/{domain}/website/favicon for storefront tab icons, allow faviconMediaId on profile PATCH, and sync website API docs.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/website-api/index.html

@@ -92,6 +92,15 @@
       <li>Cart / orders / favorites: <code>/businesses/{businessId}/...</code> + Bearer JWT.</li>
     </ol>
 
+    <h2>Branding (favicon + logos)</h2>
+    <p>
+      <code>GET /tenants/{domain}/website/favicon</code> returns
+      <code>faviconUrl</code>, <code>logoUrl</code>, <code>logoDarkUrl</code>, and
+      <code>hasDedicatedFavicon</code>. Use <code>faviconUrl</code> for the browser tab icon
+      (Next.js <code>metadata.icons</code>). When no dedicated favicon is uploaded,
+      <code>faviconUrl</code> falls back to <code>logoUrl</code>.
+    </p>
+
     <h2>User products (customer listings)</h2>
     <p>
       Marketplace-style stock listings created by customers. Public read-only under