Add delayed_job worker service to docker-compose

[neolefty]

Summary

• Adds a worker service to docker-compose.yml that automatically starts delayed_job
• Ensures background jobs are processed without manual intervention in development

Motivation

Currently, when using Docker Compose for development, background jobs (like database exports) queue but don't process because there's no delayed_job worker running. Users must manually start workers with docker compose exec app bundle exec rake jobs:work.

This PR adds a dedicated worker service that starts automatically with docker compose up.

Implementation

The worker service:

• Uses the same Dockerfile and build context as the app service
• Shares the same volumes and database connections
• Runs bundle exec rake jobs:work continuously

Test plan

• Run docker compose up with this change
• Verify the worker service starts successfully
• Test that background jobs (e.g., database exports) are processed automatically
• Ensure no negative impact on existing services

Note

This is a draft PR pending the merge of related documentation PR #4473.

🤖 Generated with Claude Code

[kleintom]

It looks like this PR includes the commit from PR #4476? I think that's okay, we'll just work with one or the other, so you can keep them both open as is for now.

I'll just mention a couple other things for now:

• it looks like your documentation pr Add documentation for database export with Docker Compose #4473 assumes this pr doesn't exist, i.e. that the job worker has to be started manually if you're running docker. If we do merge this one then we'll want to update that, but please sit tight before doing anything there for now.
• In general all end-user documentation (and some developer documentation) should go on the https://docs.taxonworks.org/ website (repository here: https://github.com/SpeciesFileGroup/taxonworks_doc) instead of in the taxonworks code repository, so we'll likely want to move your documentation pr there and fit it in with existing documentation. But again, let's hold off on that for now until we have a clearer idea of where things are heading.
• I'm not qualified to review docker changes, but I will mention that I think the reason we haven't done this in the past is because, at least on some systems, having the jobs:work worker on all the time can keep your fans running non-stop (see https://docs.taxonworks.org/develop/Code/environment.html#run-asynchronous-code-active-jobs-delayed-jobs) But maybe that's no longer as much of a concern?

[kleintom]

• at least on some systems, having the jobs:work worker on all the time can keep your fans running non-stop (see https://docs.taxonworks.org/develop/Code/environment.html#run-asynchronous-code-active-jobs-delayed-jobs) But maybe that's no longer as much of a concern?

One data point: it does cause the fans on my laptop to run non-stop (on native rails, not docker) :(