fix(oauth): persist the filtered scope after an ordinary grant

Copilot review round 11 on #2114. The docs claimed the persisted scope
"self-heals on the next grant"; on the ordinary authorization leg it
did not.

`authenticate()` never set `pendingAuthorizationScope` — only the
step-up paths did — so `completeOAuthFlow` called
`resolvePersistedScopeAfterGrant(tokens.scope, undefined)`. When the
token response omits `scope` (RFC 6749 §5.1: omitted means the grant
matched the request), the fallback was undefined, nothing was saved,
and the stale `offline_access` stayed in storage where
`resolveEffectiveGrantedScope` keeps reporting it as granted.

`authenticate()` now records the scope it actually requested, read once
from the filtering getter so what is recorded is what went out.

Gated on the filter being active rather than applied unconditionally.
The general version is arguably more RFC-correct, but it would change
what lands in storage for every server that never touched this setting,
inside a PR whose contract is that nothing changes unless the box is
unchecked. With the grant declared, request and storage agree and there
is nothing to heal.

Three tests; the omitted-scope one fails when the recording is removed.

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

@@ -315,9 +315,12 @@ export class OAuthManager {
       resourceMetadataUrl,
     });
 
+    // Read once: the getter filters (#2068), so this is what was actually
+    // requested and what the callback leg has to persist.
+    const requestedScope = provider.scope;
     const result = await mcpAuth(provider, {
       serverUrl,
-      scope: provider.scope,
+      scope: requestedScope,
       fetchFn: this.params.effectiveAuthFetch,
       resourceMetadataUrl,
     });
@@ -328,6 +331,21 @@ export class OAuthManager {
       );
     }
 
+    // #2068 — record the filtered request so `completeOAuthFlow` can persist
+    // it. `resolvePersistedScopeAfterGrant` falls back to the requested scope
+    // when the token response omits `scope` (RFC 6749 §5.1: omitted means the
+    // grant matched the request), and without this that fallback is `undefined`
+    // on the ordinary leg — only step-up ever set it. The old
+    // `offline_access` would then stay in storage, so the scope never
+    // self-heals and later satisfaction checks still read it as granted.
+    //
+    // Only when the filter is in effect. With the grant declared there is
+    // nothing to heal, and persisting a request the AS did not confirm would be
+    // a behavior change beyond this setting.
+    if (this.oauthConfig.requestRefreshToken === false && requestedScope) {
+      this.pendingAuthorizationScope = requestedScope;
+    }
+
     const capturedUrl = provider.getCapturedAuthUrl();
     if (!capturedUrl) {
       throw new Error("Failed to capture authorization URL");