[
  {
    "timestamp": "2026-04-18 21:11:44",
    "trigger": "manual",
    "old_accuracy": 0.898,
    "new_accuracy": 0.9218,
    "promoted": true,
    "improvement": 0.0238,
    "label": "DistilBERT v1",
    "description": "Manual retrain for regular check"
  }
]