Fix: Add truncate-table endpoint and improve dark mode visibility for usernames

- Added missing /api/maintenance/truncate-table endpoint to fix 404 error
- Fixed dark mode visibility issue for usernames in Current Users table
- Added explicit color styling for username strong tags in both light and dark modes

py_app/app/templates/user_management_simple.html

@@ -245,6 +245,15 @@
         background-color: rgba(255, 255, 255, 0.075) !important;
     }
     
+    /* Theme-aware username styling */
+    body.light-mode .user-management-page .table td strong {
+        color: #000 !important;
+    }
+    
+    body.dark-mode .user-management-page .table td strong {
+        color: #fff !important;
+    }
+    
     /* Theme-aware form elements */
     .user-management-page .form-control {
         border: 1px solid #ced4da !important;