Migrate SQL Schema to Prisma Schema

Convert CREATE TABLE SQL into a Prisma schema.prisma file.

category:modernization

prisma

sql

schema

migration

Prompt

Convert these CREATE TABLE statements into Prisma schema models.

Do:
- Infer primary keys and use @id/@default
- Add @unique where appropriate
- Map foreign keys to relations
- Convert enums to Prisma enums
- Preserve not-null constraints

Return a schema.prisma snippet representing the same schema.