Persona's ruling (follow-up chat-mind-20261111T150417226Z-t167): a
reader is a decider when subject is in the call's deciders; any other
reader gets no decider or answerer ids, only counts, and Huginn does it
because the card is opaque to Bifrost. CultLib's closed card (deciders
minItems 1, no count) and non-null answerer cannot carry it yet, so the
doc names the proposal to Libby and the fixtures add clearly synthetic
card fragments and a proposed non-decider record, with a test that no
account id appears in a non-decider's bytes and a decider keeps them.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>