Admin Comparisons API

{
  "success": true,
  "data": [
    {
      "comparison_id": "c1d2e3f4-...",
      "user_id": "a1b2c3d4-...",
      "prompt_text": "Explain quantum computing",
      "model1_id": "m1-uuid",
      "model2_id": "m2-uuid",
      "model1_response": "Quantum computing uses...",
      "model2_response": "Quantum computers leverage...",
      "model1_time_ms": 1200,
      "model2_time_ms": 980,
      "created_at": "2025-01-15T10:00:00Z"
    }
  ],
  "count": 50,
  "total": 12345,
  "page": 1,
  "limit": 50
}