Copilot review (#2287): the active-issuer fallback added last round could copy
issuer A's CIMD provenance onto a real dynamic registration for issuer B, since
RFC 7591 §3.2 permits B to mint the same opaque URL as its `client_id`.
Fix it at the source rather than in the resolver. `ensureCimdClientRegistration`
now runs discovery first and records the registration against the issuer it just
discovered, having confirmed *that* AS advertises
`client_id_metadata_document_supported`. Its "already registered?" check moves
after discovery and is keyed by that issuer — read ctx-less it resolved through
the active issuer and early-returned for every later one, which is what forced
the cross-issuer fallback in the first place.
`resolveSdkRegistrationKind` is therefore issuer-scoped again, with no fallback.
A second AS behind one resource now gets its own determination: CIMD when it
advertises CIMD, `dcr` otherwise — including when it mints the metadata URL as
its own `client_id`.
The cost is a discovery round trip per connect attempt rather than only the
first; noted at the call site.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lmj6X2epWpPE7ScdSKQmtA
Signed-off-by: cliffhall <cliff@futurescale.com>
4c6a9fb376