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/formwidgets/mediafinder/partials/_mediafinder.php

@@ -0,0 +1,24 @@
+<?php if ($this->previewMode && !$value): ?>
+
+    <span class="form-control" disabled="disabled"><?= e(trans('backend::lang.form.preview_no_media_message')) ?></span>
+
+<?php else: ?>
+
+    <?php
+    switch ($mode) {
+        case 'image':
+            echo $this->makePartial('image_single');
+            break;
+        case 'video':
+        case 'audio':
+        case 'document':
+            echo $this->makePartial('file_single', ['mode' => $mode]);
+            break;
+        case 'file':
+        case 'all':
+        default:
+            echo $this->makePartial('file_single', ['mode' => 'all']);
+    }
+    ?>
+
+<?php endif ?>