feat(auth): Learn's and Todo's servers take password sign-in

Their migrations add halkyon_base's five tables for passwords,
authenticators, recovery codes, resets and sign-ins begun (nothing
else), and their pruning forgets sign-ins never finished and
authenticators never confirmed, hourly, and every GitHub ID once
GitHub sign-in has ended, daily.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_server/migrations/migration_registry.txt

@@ -7,3 +7,4 @@
 20261019193547604
 20261019201213254-profiles
 20261019204122341-deletion-notices
+20261020111950710-passwords