Library generation failed (d706482)

See [failed job](https://github.com/googleapis/google-cloudevents-java/actions/runs/18184068454)

Start with the linked failed job in the GitHub Actions run and inspect its logs to identify which library-generation step failed. Use the failure details to locate the relevant generation entry point, then verify that the generation job completes successfully and produces its expected output.

索引モデルが issue の本文から書いたものです。