feat(demo_data): use translation override to ensure consistent locale

wraps actions in a `with override("en")` block to enforce the use of the English locale during execution. This ensures consistent behavior and message formatting regardless of the server's default language settings.

engine/core/management/commands/demo_data.py

@@ -10,6 +10,7 @@ from django.core.files.base import ContentFile
 from django.core.management.base import BaseCommand
 from django.db import transaction
 from django.utils import timezone
+from django.utils.translation import override
 
 from engine.blog.models import Post, PostTag
 from engine.core.models import (
@@ -86,6 +87,7 @@ class Command(BaseCommand):
 
         self._load_demo_data()
 
+        with override("en"):
             if action == "install":
                 self._install(options)
             elif action == "remove":