Authorization roles — distinct from billing/subscription.
A role governs what a user may DO (admin vs regular user); it is orthogonal to
how they pay (plans and billing are modelled separately, at the organization
level).
Role
Bases: str, Enum
A user's authorization role.
ADMIN = 'admin'
class-attribute
instance-attribute
USER = 'user'
class-attribute
instance-attribute
Regular user — the default.