feat(i18n): Implement multilingual support with Polish and English translations

- Added translation context and provider for managing language state.
- Integrated translation functionality into existing components (TaskStatusDropdown, Navigation).
- Created LanguageSwitcher component for language selection.
- Updated task statuses and navigation labels to use translations.
- Added Polish translations for various UI elements, including navigation, tasks, projects, and contracts.
- Refactored utility functions to return localized strings for deadlines and date formatting.

src/app/admin/users/page.js

@@ -12,8 +12,10 @@ import PageContainer from "@/components/ui/PageContainer";
 import PageHeader from "@/components/ui/PageHeader";
 import { LoadingState } from "@/components/ui/States";
 import { formatDate } from "@/lib/utils";
+import { useTranslation } from "@/lib/i18n";
 
 export default function UserManagementPage() {
+	const { t } = useTranslation();
 	const [users, setUsers] = useState([]);
 	const [loading, setLoading] = useState(true);
 	const [error, setError] = useState("");
@@ -54,7 +56,7 @@ export default function UserManagementPage() {
 	};
 
 	const handleDeleteUser = async (userId) => {
-		if (!confirm("Are you sure you want to delete this user?")) return;
+		if (!confirm(t('admin.deleteUser') + "?")) return;
 
 		try {
 			const response = await fetch(`/api/admin/users/${userId}`, {
@@ -141,7 +143,7 @@ export default function UserManagementPage() {
 
 	return (
 		<PageContainer>
-			<PageHeader title="User Management" description="Manage system users and permissions">
+			<PageHeader title={t('admin.userManagement')} description={t('admin.subtitle')}>
 				<Button 
 					variant="primary" 
 					onClick={() => setShowCreateForm(true)}
@@ -149,7 +151,7 @@ export default function UserManagementPage() {
 					<svg className="w-5 h-5 mr-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
 						<path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
 					</svg>
-					Add User
+					{t('admin.newUser')}
 				</Button>
 			</PageHeader>