Refactor production Docker install workflow

[Daniel-VM]

Summary

Refactors the production Docker installation workflow for pathocore-api so it can be deployed safely on the production VM without relying on workstation/testing compose behavior.

Changes

• Requires an explicit non-committed production install config via --install_conf.
• Keeps production secrets out of Docker Compose interpolation and image build context.
• Generates a runtime-only .env.prod.file for Compose metadata.
• Binds the production API to 127.0.0.1:8000 by default for reverse-proxy deployment.
• Adds production install actions for install, upgrade, and fix-permissions.
• Makes Gunicorn runtime settings configurable.
• Adds DJANGO_DEBUG=false support through the existing PathoCore runtime .env flow.
• Documents the production installation workflow.

Validation

• bash -n container_install.sh scripts/container_start.sh install.sh
• git diff --check
• docker compose -f docker-compose.prod.yml config
• container_install.sh --action fix-permissions with a temporary production config