Blog authors are currently stored independently from user accounts and are not linked to user IDs. We need to decide whether this should remain supported or whether authors should be connected to the users database.

Goal:
Define and implement a clear author ownership and identity model.

Checklist:

• Review the current blog author and user account models
• Decide whether authors should link to user IDs
• Document the behavior for existing independent authors
• Define migration requirements for linking authors to users
• Update backend models, database schema, and OpenAPI if needed
• Update author management UI and user account flows
• Define permissions for creating and editing authors
• Add migration, backend, and UI tests