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/formwidgets/mediafinder/partials/_file_single.php

@@ -0,0 +1,53 @@
+<div
+    id="<?= $this->getId() ?>"
+    class="
+        field-mediafinder
+        style-file-single
+        <?php if ($value): ?>
+            is-populated
+        <?php endif ?>
+        <?php if ($this->previewMode): ?>
+            is-preview
+        <?php endif ?>
+    "
+    data-control="mediafinder"
+    data-mediafinder-mode="<?= $mode ?? 'all' ?>"
+    <?= $field->getAttributes() ?>
+>
+
+    <!-- Find Button -->
+    <button type="button" class="btn btn-default find-button">
+        <i class="icon-folder"></i>
+    </button>
+
+    <!-- Existing value -->
+    <div class="find-object">
+        <div class="icon-container">
+            <i class="icon-file"></i>
+        </div>
+        <div class="info">
+            <h4 class="filename">
+                <span data-find-file-name><?= e(ltrim($value, '/')) ?></span>
+            </h4>
+        </div>
+        <div class="meta">
+            <a href="javascript:;" class="find-remove-button">
+                <i class="icon-times"></i>
+            </a>
+        </div>
+    </div>
+
+    <!-- Empty message -->
+    <div class="find-empty-message">
+        <span class="text-muted"><?= $prompt ?></span>
+    </div>
+
+    <!-- Data locker -->
+    <input
+        type="hidden"
+        name="<?= $field->getName() ?>"
+        id="<?= $field->getId() ?>"
+        value="<?= e($value) ?>"
+        data-find-value
+        />
+</div>