fix(api): update Prisma version in Dockerfile to match project (#2149)

The Dockerfile installed prisma@6.13.0 in the production stage but the
project uses prisma@6.18.0. Version mismatch between builder and
production stages can cause schema parsing errors.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Mariano Fuentes <marfuen98@gmail.com>

Author: 3 people