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/assets/ui/less/checkbox.balloon.less

@@ -0,0 +1,53 @@
+//
+// Balloon selector
+// --------------------------------------------------
+
+@color-balloon-control-default-text:         #ffffff;
+@color-balloon-control-default-bg:           #bcc3c7;
+@color-balloon-control-hover-bg:             @brand-secondary;
+@color-balloon-control-active-bg:            #da5700;
+
+.control-balloon-selector {
+    ul {
+        padding: 0;
+
+        // Offset the item top margin
+        margin-top: -5px;
+
+        li {
+            list-style: none;
+            display: inline-block;
+            padding: 6px 7px 5px;
+            margin-right: 5px;
+            margin-top: 6px;
+            text-transform: uppercase;
+            background: @color-balloon-control-default-bg;
+            color: @color-balloon-control-default-text;
+            font-size: 10px;
+            line-height: 100%;
+            .border-radius(@border-radius-base);
+            .transition(all 0.1s ease);
+
+            &.active {
+                background: @color-balloon-control-active-bg !important;
+            }
+        }
+    }
+
+    &.control-disabled {
+        .opacity(0.5);
+    }
+
+    &:not(.control-disabled) ul {
+        li:hover {
+            background: @color-balloon-control-hover-bg;
+            cursor: pointer;
+        }
+    }
+}
+
+.form-group {
+    .control-balloon-selector ul {
+        margin-bottom: 0;
+    }
+}