If I understand correctly, both the staging database and the production database share the same volume. Thus, production data was gone as well after deleting the volume.

1st hint - the API call only contains one volume:

    curl -X POST https://backboard.railway.app/graphql/v2 \
      -H "Authorization: Bearer [token]" \
      -d '{"query":"mutation { volumeDelete(volumeId: \"3d2c42fb-...\") }"}'

> No "this volume contains production data, are you sure?"

"If I understand correctly, "

You don't. You are missing the part where the LLM had a token which blocked access as expected. Then the LLM searched the source base, found a different token with the delete privs and then used that.

PS That warning happens in staging envs too, the LLM doesn't know which env is which by design.