curl --request PUT \
  --url https://api.mnemom.ai/v1/admin/plans/{plan_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{}'

{
  "plan_id": "<string>",
  "display_name": "<string>",
  "description": "<string>",
  "billing_model": "none",
  "base_price_cents": 123,
  "annual_price_cents": 123,
  "per_check_price": 123,
  "included_checks": 123,
  "trace_retention_days": 123,
  "feature_flags": {},
  "limits": {},
  "sort_order": 123
}