users is unique on (instance_id, email) now, so an unscoped FindOne could
return an arbitrary one of several matching users. On the login path that
means signing someone into a tenant that is not theirs.
GetUserByEmail is deleted rather than left unused. Local sign-in resolves
its instance from the host, falling back to the single instance a
self-hosted deployment has, and refuses to guess otherwise. The OIDC
cross-instance guard goes: a scoped lookup cannot return another
instance's user, which is a stronger guarantee than the check it replaces.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
mrhid6andClaude Opus 5
d703bbc4e8