fix(oauth): drop an inherited offline_access when the grant is declined

Copilot review round 4 on #2114 — a real gap, not a wording one.

Declining the grant stops the SDK *adding* `offline_access`, but the
Inspector's own storage puts it back. A successful default-on
authorization persists the scope the AS granted
(`resolvePersistedScopeAfterGrant`), `offline_access` included;
`prepareForAuth` reloads it and `authenticate` hands it to the SDK as
`scope`, which sees the token in scope and appends `prompt=consent`
again. So any server that had authorized once could uncheck the box and
still hit AADSTS90094 — the users most likely to reach for the setting
were the ones it did not help.

`scopeForDeclinedRefreshGrant` filters it out of the *request* only,
applied in the provider's `scope` getter — the one seam both
`clientMetadata.scope` and `authenticate`'s `scope:` argument read
through. An `offline_access` the user configured is honored; storage is
never rewritten, so re-checking the box restores the old behavior
instead of finding the value destroyed, and scope-satisfaction checks
still see the real grant. Verified by reverting the filter: the new e2e
regression fails.

Also from that round, both previously suppressed:

The checkbox looked effective under enterprise-managed authorization,
which never builds this provider at all — it authorizes against the
enterprise IdP with a fixed `openid offline_access`
(`ema/constants.ts:16`). It now annotates itself the way the endpoint
overrides do. The existing count assertion covered two such notices and
was named for the overrides alone; it is renamed and expects three, with
a dedicated case pinning the notice to this control so the count cannot
be met by three copies elsewhere.

And "obtains no new refresh token" was another overstatement — the AS
decides issuance, and a preconfigured client is reused with whatever its
registration already permits. Replaced with what the setting actually
controls.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013hzwzS8UvBsr4yZm7o7sev
Signed-off-by: cliffhall <cliff@futurescale.com>

core/mcp/oauthManager.ts

@@ -175,6 +175,9 @@ export class OAuthManager {
       // `authorizationParams` this is pure config off mcp.json, so it lives on
       // the provider rather than in OAuth storage.
       requestRefreshToken: this.oauthConfig.requestRefreshToken,
+      // #2068: lets the provider tell an `offline_access` the user asked for
+      // from one inherited from a previous grant's persisted scope.
+      configuredScope: this.oauthConfig.scope,
     });
 
     provider.setEventTarget(this.params.getEventTarget());