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/list.mixins.less

@@ -0,0 +1,27 @@
+// Tables
+// -------------------------
+.table-row-variant(@state; @background) {
+    // Exact selectors below required to override `.table-striped` and prevent
+    // inheritance to nested tables.
+    .table > thead > tr,
+    .table > tbody > tr,
+    .table > tfoot > tr {
+        > td.@{state},
+        > th.@{state},
+        &.@{state} > td,
+        &.@{state} > th {
+            background-color: @background;
+        }
+    }
+
+    // Hover states for `.table-hover`
+    // Note: this is not available for cells or rows within `thead` or `tfoot`.
+    .table-hover > tbody > tr {
+        > td.@{state}:hover,
+        > th.@{state}:hover,
+        &.@{state}:hover > td,
+        &.@{state}:hover > th {
+            background-color: darken(@background, 5%);
+        }
+    }
+}