frontend error management enhancement

app/templates/shop/errors/502.html

@@ -0,0 +1,33 @@
+{% extends "shop/errors/base.html" %}
+
+{% block icon %}🔧{% endblock %}
+
+{% block title %}502 - Service Temporarily Unavailable{% endblock %}
+
+{% block content %}
+{% if vendor and theme and theme.branding and theme.branding.logo %}
+<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
+{% endif %}
+
+<div class="error-icon">🔧</div>
+<div class="status-code">502</div>
+<div class="status-name">Temporarily Unavailable</div>
+<div class="error-message">
+    We're having trouble connecting to our systems. This is usually temporary. Please try again in a few moments.
+</div>
+
+<div class="action-buttons">
+    <a href="javascript:location.reload()" class="btn btn-primary">Try Again</a>
+    <a href="/" class="btn btn-secondary">Go to Home</a>
+</div>
+
+<div class="support-link">
+    If this continues, <a href="/contact">let us know</a>
+</div>
+
+{% if vendor %}
+<div class="vendor-info">
+    {{ vendor.name }}
+</div>
+{% endif %}
+{% endblock %}