GHSA-jxcw-qp4h-6jfq: PraisonAI A2U incomplete authentication fix leaves current serve command unauthenticated by default

The published A2U advisory GHSA-f292-66h9-fpmf says unauthenticated A2U event streaming was fixed in praisonai 4.5.115. Current head still exposes the same A2U subscription and event routes without authentication when the operator starts the documented CLI entrypoint:

praisonai serve a2u --host 0.0.0.0 --port 8002

The current CLI wrapper does not expose --api-key, does not install the common API-key middleware, and does not generate a token for A2U. It calls create_a2u_routes(app) directly. That helper only enforces auth if A2U_AUTH_TOKEN is already present; if the variable is missing, _authenticate_request() returns None and treats auth as disabled.

This is an incomplete-fix report for the published A2U issue, not a separate trust-model-only concern.