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/traits/ErrorMaker.php

@@ -0,0 +1,54 @@
+<?php namespace Backend\Traits;
+
+use Exception;
+use System\Classes\ErrorHandler;
+use System\Models\EventLog;
+use Winter\Storm\Exception\ApplicationException;
+
+/**
+ * Error Maker Trait
+ * Adds exception based methods to a class, goes well with `System\Traits\ViewMaker`.
+ *
+ * @package winter\wn-backend-module
+ * @author Alexey Bobkov, Samuel Georges
+ */
+trait ErrorMaker
+{
+    /**
+     * @var string Object used for storing a fatal error.
+     */
+    protected $fatalError;
+
+    /**
+     * @return boolean Whether a fatal error has been set or not.
+     */
+    public function hasFatalError()
+    {
+        return !is_null($this->fatalError);
+    }
+
+    /**
+     * @return string The fatal error message
+     */
+    public function getFatalError()
+    {
+        return $this->fatalError;
+    }
+
+    /**
+     * Sets standard page variables in the case of a controller error.
+     */
+    public function handleError($exception)
+    {
+        if (
+            $exception instanceof Exception
+            && !($exception instanceof ApplicationException)
+        ) {
+            EventLog::addException($exception);
+        }
+
+        $errorMessage = ErrorHandler::getDetailedMessage($exception);
+        $this->fatalError = $errorMessage;
+        $this->vars['fatalError'] = $errorMessage;
+    }
+}