curl https://api.getdeckle.dev/v1/usage \
  -H "Authorization: Bearer dk_live_sk_..."

{
  "period_start": "2026-02-01",
  "period_end": "2026-02-28",
  "generation_count": 742,
  "total_pages": 1856,
  "total_bytes": 89420800,
  "plan": "starter",
  "limit": 10000
}