appsettings.Development.json still targeted Musify's old own Postgres
(port 59000) with the superuser, the default RabbitMQ vhost as guest and
the admin S3 keys. They now use Infrastructure's dev ports and Musify's
own dev credentials (role, vhost and S3 identity), the same defaults as
deploy/.env.example.
The API's non-secret Zitadel settings (issuer, metadata, endpoints) move
there too, so user-secrets only need the per-machine client id.
Remove dead scaffold/config cruft and stale references left over from
recent refactors: dotnet's WebApi.http template file, the AppSettings
PascalCase/Dockerfile workaround (renamed to appsettings.json to match
convention), empty directories left behind by the auth-route and
folder-structure moves, a stale ESLint ignore, and the now-fully-applied
frontend refactor plan doc.