Simplify Dockerfile: Remove complex build-time database approach

- Remove build-time migration deployment stage that was causing CI failures
- Follow NPM pattern with runtime database initialization
- Use prisma migrate deploy instead of prisma db push for proper migration handling
- Simplify multi-stage build to just builder and production stages
- Maintain all necessary file copying and permissions setup
- Keep runtime initialization script for database setup on first run

This resolves the table creation errors during Docker build by ensuring proper migration deployment at runtime.

Author: Abdallah-khalil