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/widgets/table/DataSourceBase.php

@@ -0,0 +1,86 @@
+<?php namespace Backend\Widgets\Table;
+
+/**
+ * Base class for the Table widget data sources.
+ */
+abstract class DataSourceBase
+{
+    /**
+     * @var string Specifies a name of record's key column
+     */
+    protected $keyColumn;
+
+    /**
+     * @var integer Internal record offset
+     */
+    protected $offset = 0;
+
+    /**
+     * Class constructor.
+     * @param string $keyColumn Specifies a name of the key column.
+     */
+    public function construct($keyColumn = 'id')
+    {
+        $this->keyColumn = $keyColumn;
+    }
+
+    /**
+     * Initializes records in the data source.
+     * The method doesn't replace existing records and
+     * could be called multiple times in order to fill
+     * the data source.
+     * @param array $records Records to initialize in the data source.
+     */
+    abstract public function initRecords($records);
+
+    /**
+     * Returns a total number of records in the data source.
+     * @return integer
+     */
+    abstract public function getCount();
+
+    /**
+     * Removes all records from the data source.
+     */
+    abstract public function purge();
+
+    /**
+     * Return records from the data source.
+     * @param integer $offset Specifies the offset of the first record to return, zero-based.
+     * @param integer $count Specifies the number of records to return.
+     * @return array Returns the records.
+     * If there are no more records, returns an empty array.
+     */
+    abstract public function getRecords($offset, $count);
+
+    /**
+     * Identical to getRecords except provided with a search query.
+     */
+    public function searchRecords($query, $offset, $count)
+    {
+        return $this->getRecords($offset, $count);
+    }
+
+    /**
+     * Rewinds the the data source to the first record.
+     * Use this method with the readRecords() method.
+     */
+    public function reset()
+    {
+        $this->offset = 0;
+    }
+
+    /**
+     * Returns a set of records from the data source.
+     * @param integer $count Specifies the number of records to return.
+     * @return array Returns the records.
+     * If there are no more records, returns an empty array.
+     */
+    public function readRecords($count = 10)
+    {
+        $result = $this->getRecords($this->offset, $count);
+        $this->offset += count($result);
+
+        return $result;
+    }
+}