Implement database schema with Prisma

[Revmagi]

Set up the database layer with Prisma ORM using the designed schema.

Tasks

• Install and configure Prisma
• Implement database schema from DATABASE_SCHEMA.md
• Create initial migrations
• Set up database seeding scripts
• Configure SQLite for development
• Test basic CRUD operations

Acceptance Criteria

• Database schema matches specification
• Migrations run successfully
• Seed data populates correctly
• Ready for PostgreSQL migration