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/system/partials/_system_sidebar.php

@@ -0,0 +1,23 @@
+<div class="layout-cell sidenav-tree bg-p" data-control="sidenav-tree" data-search-input="#settings-search-input">
+    <a class="back-link" href="<?= Backend::url('system/settings') ?>"><i class="icon-angle-left"></i><?= e(trans('system::lang.settings.menu_label')) ?></a>
+
+    <div class="layout">
+        <div class="layout-row min-size">
+            <?= $this->makePartial('~/modules/system/partials/_settings_menu_toolbar.php') ?>
+        </div>
+
+        <div class="layout-row">
+            <div class="layout-cell">
+                <div class="layout-relative">
+
+                    <div class="layout-absolute">
+                        <div class="control-scrollbar" data-control="scrollbar">
+                            <?= $this->makePartial('~/modules/system/partials/_settings_menu.php') ?>
+                        </div>
+                    </div>
+
+                </div>
+            </div>
+        </div>
+    </div>
+</div>