[tobi12345]

Adds a manual beta release workflow so maintainers can select any branch in GitHub Actions and publish @langfuse/cli under the npm beta tag. Stable versions start the next minor beta (1.2.x → 1.3.0-beta.0); subsequent releases increment the shared beta sequence, and retries recognize an already-published commit.

The workflow runs version selection → preparation → publish. Preparation always builds, tests, validates both package tarballs, and prints the release plan. The dry-run option defaults to true and only gates the final publish job, which downloads the prepared canonical package and rechecks npm state before publishing. The package version changes only inside the runner; no commits, tags, or GitHub Releases are created. The existing release workflow and scripts are unchanged.

Validation

• Version-selection and release-policy tests: 21 pass, 0 fail; typecheck passed after the minor-version change.
• Full suite before the final version-selection/output edits: 102 pass, 0 fail; conformance: Total: 596/596.
• Local workflow harness verified isolated preparation/publish environments, tarball transfer, zero publishes for dry run, and one canonical publish with publication mocked.
• Release-plan output verified in both logs and the workflow summary; git diff --check passed.
• Live GitHub Actions, artifact service, and npm publishing have not been exercised.

Setup and testing

Merge the workflow into the default branch to enable manual dispatch. In Actions → Beta release → Run workflow, select a branch and leave dry run checked for the first run.

For actual publication, configure the @langfuse/cli npm trusted publisher for beta-release.yml and the npm-publish-beta GitHub environment. Allow the intended source branches and require reviewers on that environment, then run with dry run unchecked.

[tobi12345]

@claude review