bug: NotFound page is not i18n-powered

[Abdelkaderbzz]

Description

The NotFound.tsx page has hardcoded English text and doesn't use the i18n translation system.

Current state

// src/pages/NotFound.tsx
<h1 className="mb-4 text-4xl font-bold">404</h1>
<p className="mb-4 text-xl text-muted-foreground">Oops! Page not found</p>
<a href="/" className="text-primary underline hover:text-primary/90">
  Return to Home
</a>

Expected behavior

Should use translation keys like other pages:

<h1>{t('notFound.title')}</h1>
<p>{t('notFound.message')}</p>
<a href="/">{t('notFound.returnHome')}</a>

Solution

1. Add translations to src/i18n/en.ts

notFound: {
  title: '404',
  message: 'Oops! Page not found',
  returnHome: 'Return to Home',
}

2. Add translations to src/i18n/ar.ts

notFound: {
  title: '404',
  message: 'عذراً! الصفحة غير موجودة',
  returnHome: 'العودة للرئيسية',
}

3. Update NotFound.tsx to use useI18n