/add-database-railway

Set up PostgreSQL database with Prisma ORM and complete data layer.

Create:

• Prisma schema with models, relations, and indexes (schema.prisma)
• Database migrations using Prisma Migrate
• Prisma client initialization with connection pooling
• CRUD operations in Express API routes
• Query helpers for complex database operations
• Railway database environment variable configuration (DATABASE_URL)
• Database seeding script for development data
• Error handling for database operations (unique constraint, not found, timeout)
• Database utility functions in /server/utils
• README.md with database schema documentation

Include proper transaction handling, connection pooling configuration, and best practices for Prisma queries. Set up Railway PostgreSQL plugin if needed.