Sign-in (anonymous, GitHub, email codes), an account's ways in and its
deletion, the pruning and the instance's basics move into the
halkyon_base module (ADR 0014), which every Halkyon server includes.
Learn configures it in server.dart and deletes its own data with a
person through the module's hook, in the order it did. The identity
tables move unchanged: the migration records versions only. The app
calls the module's endpoints; instance.info() stays as it was.
BREAKING CHANGE: the sign-in endpoints moved into the module, so apps up
to build 20 can no longer sign in or start; minimumAppBuild is 21.
Deploy this only together with the release of build 21.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>
