{
  "websocket_url": "wss://stream.bybit.com/v5/public/linear",
  "symbol": "BTCUSDT",
  "data_dir": "data",
  "log_file": "engine.log",
  "hot_retention_hours": 12,
  "feature_retention_days": 30,
  "writer_flush_interval_ms": 500,
  "writer_batch_size": 100,
  "tick_channel_buffer": 10000,
  "maintenance_interval_minutes": 60
}