feat: VivesPOS landing on Winter CMS 1.2 — theme + plugin + Dockerfile

- Base: wintercms/winter branch 1.2 (full framework)
- Theme vivespos: Canvas 7 + Bootstrap 5 CDN, custom CSS
- Layout: deferred GTM/GA4 tracking, JSON-LD SoftwareApplication
- Partials: hero (offline-first), features, modes (offline/nube toggle),
  screenshots, pricing (3 planes), comparison, FAQ, CTA
- Plugin VivesPOS.Site with ContactForm
- Dockerfile: PHP 8.2 Apache, port 80, healthcheck
- Added winter/wn-pages, blog, sitemap, seo plugins
- Active theme set to vivespos

modules/backend/behaviors/formcontroller/views/preview.php

@@ -0,0 +1,21 @@
+<?php
+
+
+// Decide which layout we should be rendering
+$layout = $this->formLayout ?? $formConfig->formLayout ?? null;
+if (!in_array($layout, ['standard', 'sidebar', 'fancy'])) {
+    $layout = 'standard';
+}
+
+// If required, set the appropriate body classes
+$this->bodyClass = match ($layout) {
+    'fancy' => 'fancy-layout compact-container breadcrumb-flush breadcrumb-fancy',
+    'sidebar' => 'compact-container',
+    default => '',
+};
+
+// Define layout mode view path for inclusion
+$this->appendViewPath(sprintf('%s/preview/%s', __DIR__, $layout));
+
+// Render the form layout
+echo $this->makePartial(sprintf('preview/%s.php', $layout));