dc4141e718
Extract SendEventOnSession (and best-effort RunEventQueryOnSession) so the B0b spike can run multiple event ops on one already-opened v8 Event session. RegisterCmEventTag made independently callable. Behaviour-preserving (pending.md A1 broadening, Stage B0). Claude-Session: https://claude.ai/code/session_012SDSQ3AcaXqPcBtDESBRii