The channel's own ceiling (GetDescriptor().MaxExposure).
OptionalConfiguredThe agent/app/host cap from the channel's config, when set (see ReadConfiguredMaxExposure).
OptionalModelWhether the session model declares Privacy.ZeroDataRetention: true.
OptionalRequireLevels the agent requires zero data retention for.
OptionalUserThe user's own choice, when they made one.
Input to ResolveChannelExposure.