License Server — RSA-4096 + AES-256-GCM + HMAC-SHA512
HealthyPOST /api/v1/licenses/generate — Generate license
POST /api/v1/licenses/validate — Validate license
POST /api/v1/licenses/heartbeat — Usage heartbeat
GET /api/v1/public-key — Public key (offline validation)
GET /health — Health check