Refactor user account system and remove moderation integration

- Remove first_name and last_name fields from User model
- Add user deletion and social provider services
- Restructure auth serializers into separate directory
- Update avatar upload functionality and API endpoints
- Remove django-moderation integration documentation
- Add mandatory compliance enforcement rules
- Update frontend documentation with API usage examples

backend/apps/accounts/models.py

@@ -44,6 +44,10 @@ class User(AbstractUser):
         FRIENDS = "friends", _("Friends Only")
         PRIVATE = "private", _("Private")
 
+    # Override inherited fields to remove them
+    first_name = None
+    last_name = None
+
     # Read-only ID
     user_id = models.CharField(
         max_length=10,
@@ -179,7 +183,10 @@ class UserProfile(models.Model):
         """
         if self.avatar:
             # Return Cloudflare Images URL with avatar variant
-            return self.avatar.url_variant("avatar")
+            base_url = self.avatar.url
+            if '/public' in base_url:
+                return base_url.replace('/public', '/avatar')
+            return base_url
 
         # Generate default letter-based avatar using first letter of username
         first_letter = self.user.username[0].upper() if self.user.username else "U"
@@ -191,11 +198,20 @@ class UserProfile(models.Model):
         Return avatar variants for different use cases
         """
         if self.avatar:
-            return {
-                "thumbnail": self.avatar.url_variant("thumbnail"),
-                "avatar": self.avatar.url_variant("avatar"),
-                "large": self.avatar.url_variant("large"),
-            }
+            base_url = self.avatar.url
+            if '/public' in base_url:
+                return {
+                    "thumbnail": base_url.replace('/public', '/thumbnail'),
+                    "avatar": base_url.replace('/public', '/avatar'),
+                    "large": base_url.replace('/public', '/large'),
+                }
+            else:
+                # If no variant in URL, return the same URL for all variants
+                return {
+                    "thumbnail": base_url,
+                    "avatar": base_url,
+                    "large": base_url,
+                }
 
         # For default avatars, return the same URL for all variants
         default_url = self.get_avatar_url()