Shared GitHub actions and workflows for Braintrust SDK repositories.

Copy the canonical release workflow template from .github/workflows/release-<LANG>.yml and adapt it for your repository. Using it as an upstream source will enable the implemented release process to receive improvements in the future.

1. Copy the canonical template for your language into your repo's .github/workflows/. For Ruby that's release-ruby.yml — it doubles as this repo's end-to-end test and the reference implementation.
2. Adapt the marked sections — version source, gem name, working directory, and so on. The template's comments flag exactly what changes per repo; everything else is provided by the pinned actions.
3. Record the upstream version you based it on — the sdk-actions ref (commit SHA or tag) your copy was adapted from, e.g. in a header comment. Tracking it lets you (or an agent) diff your copy against a newer upstream template and sync changes deliberately as this repo evolves.
4. Bump the pinned SHA to pick up action changes. Because each action is self-contained, one SHA bump pulls in the whole updated chain.

The release workflow is composed from these actions. You normally get them via the template, but they're listed here as a reference for customizing it — each is self-contained (calls no other action in this repo), so a single SHA pin pulls in everything it needs.

Inputs and outputs are documented in each action.yml. Reference an action by commit SHA:

- uses: braintrustdata/sdk-actions/actions/release/prepare@<sha>

actions/ is generated from templates/ — never edit it by hand. See CONTRIBUTING.md for the template system and workflow.