Get usage data for a tenant's subscription.

Returns detailed usage including breakdown by claim type:

• rawat_jalan_count: Rawat Jalan claims processed
• rawat_inap_count: Rawat Inap claims processed
• free_count: Free tier usage
• charges_usage: Full breakdown from Lago

Access:

• mtk_admin: can view any tenant
• super_admin: can view tenants in their hospital group
• org_admin: can view only their own tenant

{
  "usage": {
    "charges_usage": [
      {
        "amount_cents": 0,
        "amount_currency": "IDR",
        "billable_metric": {
          "code": "claim_rawat_inap_processed",
          "name": "Claim Rawat Inap"
        },
        "events_count": 11,
        "units": "11.0"
      }
    ]
  }
}