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>

templates/game/admin/base.html.twig

@@ -48,6 +48,40 @@
             overflow-x: auto;
         }
 
+        /* simple-datatables theming to match the admin panel */
+        .datatable-top,
+        .datatable-bottom {
+            padding: 0.75rem 1rem;
+            font-size: 0.85rem;
+            color: #64748b;
+        }
+        .datatable-input {
+            border: 1px solid #e2e8f0;
+            border-radius: 6px;
+            padding: 0.35rem 0.6rem;
+            font-size: 0.85rem;
+        }
+        .datatable-selector {
+            border: 1px solid #e2e8f0;
+            border-radius: 6px;
+            padding: 0.25rem 0.4rem;
+            font-size: 0.85rem;
+        }
+        .datatable-pagination a,
+        .datatable-pagination button {
+            border-radius: 4px;
+            color: #475569;
+        }
+        .datatable-pagination a:hover,
+        .datatable-pagination button:hover {
+            background: #f1f5f9;
+        }
+        .datatable-pagination .datatable-active a,
+        .datatable-pagination .datatable-active button {
+            background: #3b82f6;
+            color: #fff;
+        }
+
         @media (max-width: 767.98px) {
             .admin-shell {
                 flex-direction: column;