Normalize RUC formatting to base-checkdigit across booking and admin views.

Accept dashed or digits-only RUC input on the backend, store a canonical dashed form, and display it consistently in booking and admin UIs.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/app/admin/users/page.tsx

@@ -3,7 +3,7 @@
 import { useState, useEffect } from 'react';
 import { useLanguage } from '@/context/LanguageContext';
 import { usersApi, eventsApi, User, Event } from '@/lib/api';
-import { parseDate } from '@/lib/utils';
+import { parseDate, formatRucDisplay } from '@/lib/utils';
 import Card from '@/components/ui/Card';
 import Button from '@/components/ui/Button';
 import { AdminPageSkeleton } from '@/components/ui/Skeleton';
@@ -314,7 +314,7 @@ export default function AdminUsersPage() {
                       </div>
                     </td>
                     <td className="px-4 py-3 text-sm text-gray-600">{user.phone || '-'}</td>
-                    <td className="px-4 py-3 text-sm text-gray-600">{user.rucNumber || '-'}</td>
+                    <td className="px-4 py-3 text-sm text-gray-600">{formatRucDisplay(user.rucNumber) || '-'}</td>
                     <td className="px-4 py-3">
                       <select value={user.role} onChange={(e) => handleRoleChange(user.id, e.target.value)}
                         className="px-2 py-1 rounded border border-secondary-light-gray text-sm">
@@ -363,7 +363,7 @@ export default function AdminUsersPage() {
                       <p className="font-medium text-sm truncate">{user.name}</p>
                       <p className="text-xs text-gray-500 truncate">{user.email}</p>
                       {user.phone && <p className="text-[10px] text-gray-400">{user.phone}</p>}
-                      {user.rucNumber && <p className="text-[10px] text-gray-400">RUC: {user.rucNumber}</p>}
+                      {user.rucNumber && <p className="text-[10px] text-gray-400">RUC: {formatRucDisplay(user.rucNumber)}</p>}
                     </div>
                     {getRoleBadge(user.role)}
                   </div>