fix(auth): filter target.list() against loggedOutProviders for consistency

The list() trap now applies a final filter against loggedOutProviders,
matching the defensive approach used in the CLI layer. While target.logout()
removes entries from underlying storage, this prevents any edge case where
a logged-out provider could appear in list() results.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/engine/src/auth-storage.ts

@@ -267,7 +267,7 @@ export function createFusionAuthStorage(): AuthStorage {
               providers.add(p);
             }
           }
-          return Array.from(providers);
+          return Array.from(providers).filter((p) => !loggedOutProviders.has(p));
         };
       }