This PR adds a read-only MaveDB file source for Galaxy, backed by https://github.com/PlushZ/mavedb-fsspec.

The file source exposes public score sets under score-sets/ and, when a user provides a MaveDB API key, authenticated user score sets under my-score-sets/.

Available files per score set include:

scores.csv
counts.csv
variants.csv
metadata.json
mapped-variants.json

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.