v1 default set is empty by design. The mechanism is wired:
future content mixins declare static defaultAliases on
themselves and collectDefaultAliases picks them up.
persistentFields: string[]
Hydrator round-trips aliases by reflection. aliasesSession is transient.
Player-facing
aliascommand, contributed via theselfslot just likesettings.yaml/var.yamlon EnvironmentMixin.