Integration tests for full Randomness flow

[Otaiki1]

Context

End-to-end verification from event to reveal tx.

Goal

Add integration tests with mocked Horizon and Soroban RPC.

Contributor guide

1. Directory: oracle/
2. Trigger mock event -> check queue job -> check computed randomness -> check submission.
3. Use a local Soroban RPC if possible (e.g. standalone node).
4. Verify whole cycle takes < N seconds.
5. Test with both VRF and PRNG paths.

References

• Oracle ARCHITECTURE - Flow diagram.

[Kenlachy]

@Kenlachy has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

I would like to work on this issue because validating the full randomness flow end to end is essential for correctness, security, and trust. Randomness systems often involve multiple components, and integration tests ensure they work together reliably under real conditions.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Kenlachy to this issue.