Fix and automate local environment setup

[erick-GeGe]

Description

• Add MongoDB to docker-compose and Makefile resources for local setup.
• Add project-downloader to build services and rename Dockerfile-downloader to Dockerfile-project-downloader to match the expected image name.
• Add make setup-minio-bucket target to automate MinIO bucket creation and public policy (replaces manual UI steps).
• Skip _candidate image suffix in local mode (CREDENTIALS=local) in get_candidate_image() since local registry builds directly to production tag.

Issue

• Github Issue ID.

Checklist before requesting a review

• I have performed a self-review of my code.
• My code follows the style guidelines of this project.
• I have made corresponding changes to the documentation.
• New and existing tests pass locally with my changes.
• If this change is a core feature, I have added thorough tests.
• If this change affects or depends on the behavior of other estela repositories, I have created pull requests with the relevant changes in the affected repositories. Please, refer to our official documentation.
• I understand that my pull request may be closed if it becomes obvious or I did not perform all of the steps above.

[joaquingx]

Do we need to add a documentation about the candidate logic not working for local deployments? @erick-GeGe

[erick-GeGe]

Do we need to add a documentation about the candidate logic not working for local deployments? @erick-GeGe

Yes, I'll add a note about that in the local deployment docs. I'll also document the new MongoDB service in the Docker Compose setup and the MinIO initialization script.

[github-actions]

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