The persistent tier defaulted ON when the config key was absent, while
gstack-config's DEFAULTS table answers 'off' for the same question —
preamble-spawned daemons and direct $B daemons disagreed about consent.
Absent key/file now means disabled; community/anonymous enable; env
kill-switch still beats everything. Both config.yaml consumers now
share one readGstackConfigYamlKey reader. 12-case consent suite.