List batch verification tasks

curl -X GET \
  'https://api.boltroute.ai/api/v1/tasks?limit=10&offset=0&is_file_backed=true'

{
  "tasks": [
    {
      "id": "550e8400-e29b-41d4-a716-446655440000",
      "user_id": "550e8400-e29b-41d4-a716-446655440000",
      "webhook_url": "https://example.com/webhook",
      "is_file_backed": true,
      "file": {
        "upload_id": "550e8400-e29b-41d4-a716-446655440111",
        "task_id": "550e8400-e29b-41d4-a716-446655440000",
        "filename": "emails.csv",
        "email_count": 123,
        "status": "completed",
        "created_at": "2025-01-01T12:00:00Z",
        "updated_at": "2025-01-01T12:05:00Z"
      },
      "source": "frontend",
      "created_at": "2025-01-01T12:00:00Z",
      "updated_at": "2025-01-01T12:05:00Z",
      "metrics": {
        "total_email_addresses": 2,
        "job_status": {
          "pending": 0,
          "processing": 0,
          "completed": 2,
          "failed": 0
        },
        "progress": 1,
        "progress_percent": 100,
        "verification_status": {
          "valid": 2,
          "invalid": 0,
          "catchall": 0,
          "invalid_syntax": 0,
          "disposable_domain": 0,
          "unknown": 0,
          "role_based": 0,
          "disposable_domain_emails": 0
        },
        "last_verification_requested_at": "2025-01-01T12:00:01Z",
        "last_verification_completed_at": "2025-01-01T12:04:59Z"
      }
    }
  ],
  "count": 1,
  "limit": 10,
  "offset": 0
}