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

themes/demo/assets/vendor/bootstrap/less/grid.less

@@ -0,0 +1,84 @@
+//
+// Grid system
+// --------------------------------------------------
+
+
+// Container widths
+//
+// Set the container width, and override it for fixed navbars in media queries.
+
+.container {
+  .container-fixed();
+
+  @media (min-width: @screen-sm-min) {
+    width: @container-sm;
+  }
+  @media (min-width: @screen-md-min) {
+    width: @container-md;
+  }
+  @media (min-width: @screen-lg-min) {
+    width: @container-lg;
+  }
+}
+
+
+// Fluid container
+//
+// Utilizes the mixin meant for fixed width containers, but without any defined
+// width for fluid, full width layouts.
+
+.container-fluid {
+  .container-fixed();
+}
+
+
+// Row
+//
+// Rows contain and clear the floats of your columns.
+
+.row {
+  .make-row();
+}
+
+
+// Columns
+//
+// Common styles for small and large grid columns
+
+.make-grid-columns();
+
+
+// Extra small grid
+//
+// Columns, offsets, pushes, and pulls for extra small devices like
+// smartphones.
+
+.make-grid(xs);
+
+
+// Small grid
+//
+// Columns, offsets, pushes, and pulls for the small device range, from phones
+// to tablets.
+
+@media (min-width: @screen-sm-min) {
+  .make-grid(sm);
+}
+
+
+// Medium grid
+//
+// Columns, offsets, pushes, and pulls for the desktop device range.
+
+@media (min-width: @screen-md-min) {
+  .make-grid(md);
+}
+
+
+// Large grid
+//
+// Columns, offsets, pushes, and pulls for the large desktop device range.
+
+@media (min-width: @screen-lg-min) {
+  .make-grid(lg);
+}