feat(API): 에러 메시지 다국어 추가

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

lang/en/error.php

@@ -111,4 +111,12 @@
         'invalid_status_transition' => 'Invalid status transition.',
     ],
 
+    // Work order related
+    'work_order' => [
+        'not_found' => 'Work order not found.',
+        'cannot_delete_in_progress' => 'Cannot delete in progress or completed work order.',
+        'not_bending_process' => 'This is not a bending process.',
+        'invalid_transition' => "Cannot transition status from ':from' to ':to'. Allowed statuses: :allowed",
+    ],
+
 ];