F3.1: future FFXIV patches can add new ChatTypes that aren't on any
existing whitelist. With the field defaulted to false a new install
would silently drop those channels until the user opts in. New configs
now start with PrivacyPersistUnknownChannels=true via a constant in
PrivacyDefaults. Existing configs keep their explicit choice — the
deserializer overrides the initializer, so no migration and no schema
bump.
JonKazama-Hellion
58e754c169