fix: correct ForumConfigService repository_type

Fixed bug where ForumConfigService was incorrectly using
AllowedUsersConfigRepository instead of ForumConfigRepository.
This would cause ForumConfig CRUD operations to fail.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: JacobCoffee

services/api/src/byte_api/domain/guilds/services.py

@@ -133,7 +133,7 @@ class ForumConfigRepository(SQLAlchemyAsyncRepository[ForumConfig]):
 class ForumConfigService(SQLAlchemyAsyncRepositoryService[ForumConfig]):
     """Handles basic operations for the guilds' Forum config."""
 
-    repository_type = AllowedUsersConfigRepository
+    repository_type = ForumConfigRepository
     match_fields = ["guild_id"]
 
     async def to_model(self, data: ModelDictT[ForumConfig], operation: str | None = None) -> ForumConfig: