Get provider statistics

curl --request GET \
  --url https://app.sendmux.ai/api/v1/providers/stats \
  --header 'Authorization: Bearer <token>'

{
  "ok": true,
  "data": {
    "total": 12,
    "active": 8,
    "inactive": 3,
    "error": 1,
    "pending": 0,
    "by_type": {
      "smtp": 6,
      "gmail_api": 4,
      "outlook_api": 2
    },
    "by_status": {
      "active": 8,
      "inactive": 3,
      "error": 1,
      "pending": 0
    }
  },
  "meta": {
    "request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
  }
}