Add OIDC User Metadata Storage

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe. Currently, the OIDC provider returns user metadata (e.g., whether the user is a guest or internal), but there is no built-in way to store this information in docs. This limits our ability to:

• Generate statistics based on user roles.
• Dynamically adjust permissions or abilities (e.g., restrict guests compared to internal users).

Describe the solution you'd like Add a feature to:

1. Store OIDC user metadata (e.g., user_type: guest|internal) in a structured format within docs.
2. Expose this metadata for:
   • Analytics (e.g., tracking usage by user type).
   • Role-based access control (RBAC) to enforce permissions (e.g., guests have read-only access, while internal users can edit).

Considered drawbacks:

• Additional storage requirements for metadata.
• Potential complexity in synchronizing metadata updates if user roles change.