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/layouts/_custom_styles.php

@@ -0,0 +1,14 @@
+<?php
+    use Backend\Models\BrandSetting;
+    use Backend\Models\EditorSetting;
+?>
+<?php if (BrandSetting::isConfigured() || BrandSetting::isBaseConfigured()): ?>
+    <style>
+        <?= BrandSetting::renderCss() ?>
+    </style>
+<?php endif ?>
+<?php if (EditorSetting::isConfigured()): ?>
+    <style>
+        <?= EditorSetting::renderCss() ?>
+    </style>
+<?php endif ?>