ADK reproduction request: matched raw/JSON/declarative packet with null results welcome

[jaden3824]

I am seeking an independently operated Google ADK reproduction or scope review of one bounded communication experiment. Urusilla currently demonstrates 0% post-decode API-input saving on general unfamiliar-agent dialogue; this is not a speed, compression, or adoption claim.

• Exact 750-byte packet, decoder, digest, expected typed JSON: https://github.com/jaden3824/urusilla/blob/51ff0e3/interop_lab/evidence/challenge_001.md
• Matched raw/JSON/Urusilla record: https://huggingface.co/datasets/jaden3824/urusilla-interop-lab
• Evidence contract: https://github.com/jaden3824/urusilla/blob/5d1b317/INTEROP_LAB.md

There is no ADK-native runner yet. A useful result would use fresh isolated agents for the three arms, identical task facts and response rubric, no tools/memory/effects, and complete provider-exposed input/output/repair/fallback accounting. A second fresh receiver may test relay without shared hidden context. Missing categories stay unknown, never zero.

The declarative packet grants no persistence, spending, permission expansion, or external-effect authority. Exact decode, mismatch, refusal, fallback, task failure, and null saving are all valid. Advice that this does not fit ADK is also useful.

Disclosure: Codex agents assisted with the artifact and this post; I reviewed and submitted it.