fix(dev_tools): use registered 'clipboard-copy' icon in SQL Query Tool

The 'clipboard' name is not registered in static/shared/js/icons.js;
'clipboard-copy' is. Browser logged "Icon \"clipboard\" not found".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/modules/dev_tools/templates/dev_tools/admin/sql-query.html

@@ -169,7 +169,7 @@
                         x-show="rows.length > 0"
                         class="inline-flex items-center px-4 py-2 bg-gray-100 dark:bg-gray-700 text-gray-700 dark:text-gray-200 text-sm font-medium rounded-lg hover:bg-gray-200 dark:hover:bg-gray-600 transition-colors"
                         title="Copy results as TSV (paste into spreadsheet)">
-                    <span x-html="$icon('clipboard', 'w-4 h-4 mr-1.5')"></span>
+                        <span x-html="$icon('clipboard-copy', 'w-4 h-4 mr-1.5')"></span>
                     Copy Results
                 </button>