curl --request GET \
  --url 'https://backend.testeswaffle.org/subscription/?period=month&newsletter=thenews' \
  --header 'Authorization: Bearer seu-token-jwt'

{
  "success": true,
  "data": {
    "total_subscribers": 45230,
    "new_subscribers": 3421,
    "unsubscribes": 234,
    "growth_rate": 7.8,
    "by_newsletter": {
      "thenews": {
        "total": 25430,
        "new": 2100,
        "unsubscribed": 120,
        "active_rate": 94.5
      },
      "thebizness": {
        "total": 12800,
        "new": 890,
        "unsubscribed": 65,
        "active_rate": 92.3
      }
    },
    "by_source": {
      "organic": 15230,
      "referral": 12450,
      "social": 10550,
      "paid": 7000
    },
    "timeline": [
      {
        "date": "2024-01-01",
        "subscribers": 41809,
        "new": 125
      },
      {
        "date": "2024-01-02",
        "subscribers": 41934,
        "new": 130
      }
    ]
  }
}