curl -X POST https://rolearn.dev/api/dev-lens/analyze \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -F "file=@retention_data.csv" \
  -F "genre=simulator"

{
  "file_type": "retention",
  "metrics": {
    "d1_retention": 0.42,
    "d7_retention": 0.18,
    "d30_retention": 0.08
  },
  "benchmarks": {
    "d1_vs_genre": "+5%",
    "d7_vs_genre": "-2%"
  },
  "patterns": [
    "Retention drops sharply after Day 3 — consider adding a Day 3 reward"
  ],
  "ai_analysis": "Your retention curve shows strong D1 but a cliff at D3-D7. This pattern is common in simulators that lack mid-game progression...",
  "recommendations": [
    "Add a progression milestone between Day 3-5",
    "Implement a daily reward calendar"
  ]
}