v0.7.13 — paid-agent gating fix

Paid agents are no longer short-circuited locally. /hep-call <paid-slug> now goes through the same server policy as everyone: Agentlas sign-in (automatic) + the server credit gate (OWN_CALL_CREDITS for your own cloud packages), instead of a local blocked_paid_overlap dead-end. Credit/auth refusals are surfaced cleanly; the runtime never reads local source to role-play a paid agent.