curl -X GET "https://api.usegately.com/api/v1/user-plans/current" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "X-User-ID: user_123"

{
  "subscription": {
    "id": "sub_123",
    "plan_id": "plan_456",
    "plan_name": "Pro Plan",
    "status": "active",
    "current_period_start": "2024-01-01T00:00:00Z",
    "current_period_end": "2024-02-01T00:00:00Z",
    "cancel_at_period_end": false
  }
}