Returns state, expiresAt/daysRemaining, lastValidatedAt, message
(LicenseMessageRenderer.forState), and a limits[] array where each
entry carries key/current/cap/source ("license" vs "default"). Adds
public AgentRegistryService.liveCount() so max_agents can be reported
from the in-memory registry.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>