feat: internationalize internship application status messages and add Swedish/German language support

lang/en/career.php

@@ -60,6 +60,13 @@ return [
     'message_placeholder' => 'Your skills, experiences, and anything you want to add...',
     'cv_description' => 'PDF, DOC, DOCX (Max. 5MB)',
 
+    // Messages
+    'success' => 'Success!',
+    'ok' => 'OK',
+    'error' => 'Error!',
+    'validation_error' => 'Please check the errors in the form.',
+    'error_message' => 'An error occurred while submitting the application. Please try again.',
+
     'remote_work_title' => 'Fully Remote Work',
     'remote_work_details' => 'Team coordination is maintained through daily standup meetings. Working hours are more flexible in some projects. Interns are evaluated in one or more real projects suitable for their CV and skills.',
     'application_conditions_title' => 'Application Conditions',