build(docker): Switch app, Postgres, and Redis images to Alpine

[claudiocebpaz]

Summary

• Migrates Dockerfile build/runtime stages to Alpine-based Ruby images.
• Replaces Debian package installation (apt) with Alpine equivalents (apk) while preserving the existing asset build flow.
• Updates compose.yaml service images to Alpine variants for Postgres and Redis.

How to test

• docker compose build
• docker compose up
• Verify web, postgres, and redis start correctly.
• Run project checks/tests via the wrapper (./run ...).

Additional context

• This Alpine-based setup has been running in production in my environment for an extended period.
• Operationally, it has been stable, and resource consumption has been lower compared to the previous Debian-based configuration.

[nickjj]

Hi,

I appreciate the PR but I don't think switching to Alpine is the right fit for this project.

Can you provide exhaustive benchmarks on how you directly compared resource consumption between Debian and Alpine and Alpine has been much lower? Preferably separate CPU, memory, network and disk I/O stats at runtime along with the test projects you used to do this (if possible) and how it was measured.