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/assets/images/secondary-tab-shape-content.svg

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 13.0.0, SVG Export Plug-In  -->
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd" [
+	<!ENTITY ns_flows "http://ns.adobe.com/Flows/1.0/">
+]>
+<svg version="1.1"
+	 xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:a="http://ns.adobe.com/AdobeSVGViewerExtensions/3.0/"
+	 x="0px" y="0px" width="77px" height="25px" viewBox="0 -0.167 77 25" enable-background="new 0 -0.167 77 25"
+	 xml:space="preserve">
+<defs>
+</defs>
+<path fill="#FFFFFF" d="M60,25h15c-5.037,0-5-25-15-25V25z"/>
+<g>
+	<path fill="#FFFFFF" d="M15,25H0C5.037,25,5,0,15,0V25z"/>
+</g>
+</svg>