Add pagination/search/sort to the admin tables that can grow large

Uses simple-datatables (vanilla JS, no jQuery needed) on the Users,
Sessions, Email Log, and Feedback tables, since those grow with real
usage. Left Games (small, admin-curated) and Hints (row order is
meaningful - "checked in order" - a sortable column would mislead)
untouched.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

assets/admin-datatables.js

@@ -0,0 +1,22 @@
+import { DataTable } from 'simple-datatables';
+import 'simple-datatables/dist/style.css';
+
+// Paginate/search/sort any admin table opted in via class="admin-datatable".
+// Kept off tables that are admin-curated and stay small (games) or where row
+// order is meaningful and must not be disturbed by sorting (hints).
+document.addEventListener('DOMContentLoaded', () => {
+    document.querySelectorAll('table.admin-datatable').forEach((table) => {
+        new DataTable(table, {
+            perPage: 25,
+            perPageSelect: [10, 25, 50, 100],
+            searchable: true,
+            sortable: true,
+            labels: {
+                placeholder: 'Search...',
+                perPage: '{select} entries per page',
+                noRows: 'No matching entries found',
+                info: 'Showing {start} to {end} of {rows} entries',
+            },
+        });
+    });
+});