Restyle toasts and centralize friendly error handling.

Replace the default react-toastify look with project-styled toast cards
(icon chip, rounded shell, RTL-aware container, type-colored progress
bar) via a new notify helper and globals.css overrides.

Add a central error layer (src/lib/errors.ts): classify any caught error
by HTTP status / network condition, log the full technical detail
(including the raw backend message) to the console only, and surface a
friendly, localized message to the user. Raw backend messages are no
longer shown. All ~190 toast call sites across 22 files move to notify,
routing backend errors through notify.error(err, fallback); dead
apiErrorMessage/formatApiError helpers removed. Adds an `errors` section
to the fa/en dictionaries.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/app/[lang]/dashboard/tickets/page.tsx

@@ -6,7 +6,7 @@ import { Link } from '@/i18n/Link';
 import { useT, useLocale } from '@/i18n/I18nProvider';
 import api from '@/lib/api';
 import { useAuthStore } from '@/lib/store';
-import { toast } from 'react-toastify';
+import { notify } from '@/lib/notify';
 import type { Ticket, CreateTicketDto, TicketDepartment, TicketPriority } from '@/types';
 import { Wrench, Briefcase, Ticket as TicketIcon, X } from 'lucide-react';
 import { Select } from '@/components/ui/select';
@@ -56,12 +56,12 @@ export default function TicketsPage() {
   const createMutation = useMutation({
     mutationFn: (data: CreateTicketDto) => api.post('/tickets', data).then((r) => r.data),
     onSuccess: () => {
-      toast.success(tk.createdSuccess);
+      notify.success(tk.createdSuccess);
       queryClient.invalidateQueries({ queryKey: ['my-tickets'] });
       setShowCreate(false);
       setForm({ subject: '', department: availableDepartments[0]?.value || 'technical', priority: 'medium', message: '' });
     },
-    onError: (err: any) => toast.error(err.response?.data?.message || tk.createFailed),
+    onError: (err: any) => notify.error(err, tk.createFailed),
   });
 
   const handleSubmit = (e: React.FormEvent) => {