Package data keeps GnoRadio's state apart from its rules. It knows nothing of music: ordered collections of string keys to string values, and a vault for the coins of promo budgets (vault.gno).
Each collection belongs to a role, the prefix of its name ("catalog/…"). Only that role's writer realm writes it; anyone reads. A release (new writers for one or more roles) takes over DELAY after every new realm said Ready, all at once, and no data moves. The owner proposes and cancels releases, pauses and resumes roles, passes the role on or renounces it, and can replace the guardian 2x DELAY after saying so. The guardian can only pause and cancel a release. This realm is never replaced: keep it small.
Writers is the state of every role, as JSON: {"owner","pendingOwner", "guardian","pendingGuardian","nextGuardian","guardianAt","at","roles": {"catalog":{"writer","paused","proposed","ready"},…}}. at is the unix time a ready release takes over, guardianAt the time nextGuardian (the owner's GuardianReplace) does.
gnokey query vm/qeval -remote "https://rpc.onyx.testnets.gno.land" -data "gno.land/r/nym-alexiscolin000/gnoradio/data.Writers()"