Refactor test utilities and enhance ASGI settings

- Cleaned up and standardized assertions in ApiTestMixin for API response validation.
- Updated ASGI settings to use os.environ for setting the DJANGO_SETTINGS_MODULE.
- Removed unused imports and improved formatting in settings.py.
- Refactored URL patterns in urls.py for better readability and organization.
- Enhanced view functions in views.py for consistency and clarity.
- Added .flake8 configuration for linting and style enforcement.
- Introduced type stubs for django-environ to improve type checking with Pylance.

core/admin.py

@@ -1,29 +1,26 @@
 from django.contrib import admin
-from django.contrib.contenttypes.models import ContentType
 from django.utils.html import format_html
 from .models import SlugHistory
 
+
 @admin.register(SlugHistory)
 class SlugHistoryAdmin(admin.ModelAdmin):
-    list_display = ['content_object_link', 'old_slug', 'created_at']
-    list_filter = ['content_type', 'created_at']
-    search_fields = ['old_slug', 'object_id']
-    readonly_fields = ['content_type', 'object_id', 'old_slug', 'created_at']
-    date_hierarchy = 'created_at'
-    ordering = ['-created_at']
+    list_display = ["content_object_link", "old_slug", "created_at"]
+    list_filter = ["content_type", "created_at"]
+    search_fields = ["old_slug", "object_id"]
+    readonly_fields = ["content_type", "object_id", "old_slug", "created_at"]
+    date_hierarchy = "created_at"
+    ordering = ["-created_at"]
 
     def content_object_link(self, obj):
         """Create a link to the related object's admin page"""
         try:
             url = obj.content_object.get_absolute_url()
-            return format_html(
-                '<a href="{}">{}</a>',
-                url,
-                str(obj.content_object)
-            )
+            return format_html('<a href="{}">{}</a>', url, str(obj.content_object))
         except (AttributeError, ValueError):
             return str(obj.content_object)
-    content_object_link.short_description = 'Object'
+
+    content_object_link.short_description = "Object"
 
     def has_add_permission(self, request):
         """Disable manual creation of slug history records"""