fix(embed): honor redirect URL after submit + keep the success message themed

- The `redirectUrl` setting was never applied — on submit the embed now redirects
  to it (window.location.href) when set, otherwise shows the success message.
- The success message was appended after the themed <form> was cleared, losing the
  theme. It's now wrapped in .sfb-form with the resolved --sfb-* vars re-applied, so
  it stays styled (notably on third-party embeds where there's no card to inherit
  from). Small padding tweak on .sfb-success.

Verified end-to-end: a cross-origin embed auto-submits and navigates to the redirect.

Author: devCluna

admin/src/form-css.ts

@@ -29,7 +29,7 @@ select.sfb-input { appearance: none; cursor: pointer; }
 .sfb-heading { font-size: 18px; font-weight: 700; color: var(--sfb-text, #1f1f33); margin: 4px 0; }
 .sfb-paragraph { font-size: 14px; color: var(--sfb-muted, #666687); margin: 4px 0; line-height: 1.6; }
 .sfb-divider { border: none; border-top: 1px solid var(--sfb-border, #dcdce4); margin: 4px 0; }
-.sfb-success { font-size: 15px; color: #27ae60; font-weight: 600; }
+.sfb-success { font-size: 16px; color: #27ae60; font-weight: 600; padding: 8px 0; margin: 0; }
 .sfb-error { font-size: 13px; color: #ee5e52; margin-bottom: 12px; }
 .sfb-field-error { font-size: 12px; color: #ee5e52; margin: 4px 0 0; }
 .sfb-field--error .sfb-input, .sfb-field--error .sfb-radio-group { border-color: #ee5e52 !important; }

server/src/controllers/form.ts

@@ -225,11 +225,23 @@ function embedScript(): string {
           });
         })
         .then(function () {
+          // redirect after submit, if configured
+          var redirect = form.settings && form.settings.redirectUrl;
+          if (redirect) { window.location.href = redirect; return; }
+          // otherwise show the success message — wrapped in .sfb-form + re-applying the
+          // theme so it stays styled (the themed <form> we just cleared is gone)
+          var wrap = document.createElement('div');
+          wrap.className = 'sfb-form';
+          if (form.settings && form.settings.themeVars) {
+            var stv = form.settings.themeVars;
+            for (var sk in stv) { if (Object.prototype.hasOwnProperty.call(stv, sk)) wrap.style.setProperty(sk, stv[sk]); }
+          }
           var msg = document.createElement('p');
           msg.className = 'sfb-success';
           msg.textContent = (form.settings && form.settings.successMessage) || 'Form submitted successfully';
+          wrap.appendChild(msg);
           el.innerHTML = '';
-          el.appendChild(msg);
+          el.appendChild(wrap);
         })
         .catch(function (body) {
           btn.disabled = false;