feat(demo): add reset-to-defaults link on snapshot tables multi-select

Authored-by: Moko Consulting
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/packages/plg_system_mokowaas/Field/SnapshotTablesField.php

@@ -154,6 +154,17 @@ class SnapshotTablesField extends FormField
 
 		$html .= '</select>';
 
+		// "Reset to defaults" link
+		$defaultsJson = htmlspecialchars(json_encode(self::DEFAULT_TABLES), ENT_QUOTES, 'UTF-8');
+		$html .= '<div class="mt-1">'
+			. '<a href="#" class="small" onclick="'
+			. 'var sel=document.getElementById(\'' . $this->id . '\');'
+			. 'var defs=' . $defaultsJson . ';'
+			. 'Array.from(sel.options).forEach(function(o){o.selected=defs.indexOf(o.value)!==-1;});'
+			. 'return false;'
+			. '"><span class="icon-refresh" aria-hidden="true"></span> Reset to defaults</a>'
+			. '</div>';
+
 		return $html;
 	}
 }