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/cms/controllers/index/_button_lastmodified.php

@@ -0,0 +1,8 @@
+<?php if (isset($lastModified)): ?>
+    <span
+        class="btn empty wn-icon-calendar"
+        title="<?= e(trans('backend::lang.media.last_modified')) ?>: <?= $lastModified ?>"
+        data-toggle="tooltip"
+        data-placement="right">
+    </span>
+<?php endif; ?>