Fix CRLF line endings in Dockerfile

[Brrake]

Fix CRLF line endings in Dockerfile

Summary

Fix container startup error '[FATAL tini (6)] exec /usr/local/bin/entrypoint.sh failed: No such file or directory' when building and running the local image.

Linked issue

Closes #578

Type of change

• Bug fix
• New feature
• Refactor
• Tests only
• Documentation only
• CI / tooling

Why this approach

I tried to build a local Docker image using the Dockerfile. The build completed successfully, but the container failed to start with [FATAL tini (6)] exec /usr/local/bin/entrypoint.sh failed: No such file or directory, which was caused by incorrect line endings in the entrypoint script.

Testing

1. Built the Docker image locally.
2. Ran the container after applying the line ending fix.
3. Verified that the container starts correctly and no longer fails with [FATAL tini (6)] exec /usr/local/bin/entrypoint.sh failed: No such file or directory.

No additional automated tests were needed, since the change only affects shell script line endings and container startup behavior.

• I ran existing tests relevant to this change.
• I added or updated tests where needed.
• No tests were needed, and I explained why.

Documentation

• I updated documentation or comments where needed.
• No documentation updates were needed.

Author checklist

• This PR is focused on one concern.
• This PR is reasonably small and reviewable.
• I read and followed CONTRIBUTING.md.
• I can explain every code change in this PR.
• I will respond to review feedback myself.

AI usage disclosure

• No AI tools were used.
• AI tools were used for part of this PR, and I personally reviewed and verified all changes.

If AI tools were used, briefly describe how:

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