The overrides are per-server configuration for the *resource* server's
authorization server, but the fetch wrapper that applies them is shared
with the enterprise-managed (EMA) flow, whose IdP OIDC discovery runs
through the same fetch and satisfies the metadata predicate. An
authorization override could therefore redirect the IdP login to the
resource AS, and a token override could send the IdP code or refresh
token there.
OAuthManager.getEndpointOverrides() now returns nothing when the server
is enterprise-managed — the same boundary redirectToExternalAuthorization
draws for the custom authorization parameters (#2018) — with a regression
test, the note surfaced on both form fields, and the rule documented.
Signed-off-by: cliffhall <cliff@futurescale.com>