feat(dashboard): show admin hints and add the hints admin page

src/components/AppHeader.jsx

@@ -1,6 +1,6 @@
 import {Link, NavLink, useLocation, useNavigate} from 'react-router-dom';
 import {useTranslation} from 'react-i18next';
-import {ChartColumn, Dices, Eye, Languages, LayoutDashboard, Library, LogOut, Moon, Settings, Shield, Sun} from 'lucide-react';
+import {ChartColumn, Dices, Eye, Languages, LayoutDashboard, Library, LogOut, Megaphone, Moon, Settings, Shield, Sun} from 'lucide-react';
 import {toast} from 'sonner';
 
 import {Badge} from '@/components/ui/badge';
@@ -112,9 +112,14 @@ export default function AppHeader({isAuthenticated, onLogout}) {
                                     <Link to="/settings"><Settings/>{t('NAV.SETTINGS')}</Link>
                                 </DropdownMenuItem>
                                 {isAdmin && !viewingAs && (
-                                    <DropdownMenuItem asChild>
-                                        <Link to="/admin/users"><Shield/>{t('NAV.ADMIN')}</Link>
-                                    </DropdownMenuItem>
+                                    <>
+                                        <DropdownMenuItem asChild>
+                                            <Link to="/admin/users"><Shield/>{t('NAV.ADMIN')}</Link>
+                                        </DropdownMenuItem>
+                                        <DropdownMenuItem asChild>
+                                            <Link to="/admin/hints"><Megaphone/>{t('NAV.ADMIN_HINTS')}</Link>
+                                        </DropdownMenuItem>
+                                    </>
                                 )}
                                 {isAdmin && (
                                     <DropdownMenuSub>