IsStillActiveMemberAsync is now the single reading of "this subject is
still an Active member", called by the token and userinfo endpoints.
The stale-client test runs on OpenIddict's own non-bulk deletion path
(DisableBulkOperations) instead of a row-only store, with two stale
clients (one a case variant of the configured id) and asserts their
tokens and authorizations are gone and the configured client's remain.
Not yet verified on Yggdrasil at commit time.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
ec4acfaa83