fix(auth): revoke API tokens when an admin is demoted (#6831) (#6832)

core/auth.py

@@ -463,6 +463,17 @@ class AuthManager:
                 admin_count = sum(1 for d in self.users.values() if d.get("is_admin"))
                 if admin_count <= 1:
                     return SetAdminResult.LAST_ADMIN
+                # Token creation is admin-only and a demoted user can neither
+                # list nor revoke their tokens, so purge them with the role.
+                # Done before the flag flips: if the token store fails the
+                # exception propagates and the user is still an admin.
+                from core.database import get_db_session, ApiToken
+                with get_db_session() as db:
+                    removed_tokens = db.query(ApiToken).filter(ApiToken.owner == username).delete()
+                if removed_tokens:
+                    logger.info(
+                        f"Revoked {removed_tokens} API token(s) owned by demoted admin '{username}'"
+                    )
             # Write order matters for lock-free readers: get_privileges()
             # reads without _config_lock and trusts is_admin, so the admin
             # flag must be flipped while the stored map is safe to expose —