Liveness + readiness check del worker (DB + Redis)

Restituisce 200 se DB e Redis rispondono entro 2s, 503 altrimenti. Usato da Dokploy/Traefik per il routing healthy. Vedi packages/worker/src/services/health.service.ts.

curl -X GET "https://example.com/health"

{  "status": "ok",  "service": "string",  "checks": {    "db": {      "ok": true,      "latencyMs": 0,      "error": "string"    },    "redis": {      "ok": true,      "latencyMs": 0,      "error": "string"    }  }}