{
  "serial":      "PCMCM-XXXX-XXXX-XXXX-XXXX",
  "hwid":        "a1b2c3…",
  "app_version": "1.0.0",
  "client_ts":   1782112711
}

// response — signed in headers
X-Server-Signature: 63b14e…1b7b
{
  "ok": true,
  "status": "active",
  "token":  "…",
  "payload": { "feature": "core", "ttl": 300 }
}

↓ PCMCM-Setup-0.1.0.exe