feat: Refactor user management to replace email with username across the application

src/components/ProjectForm.js

@@ -178,7 +178,7 @@ export default function ProjectForm({ initialData = null }) {
 								<option value="">{t('projects.unassigned')}</option>
 								{users.map((user) => (
 									<option key={user.id} value={user.id}>
-										{user.name} ({user.email})
+										{user.name} ({user.username})
 									</option>
 								))}
 							</select>