Repair a multimodal satellite flood change-detection audit so it compares before/after imagery, masks…

Repair a multimodal satellite flood change-detection audit so it compares before/after imagery, masks…: a task in Long-Horizon Terminal-Bench (LHTB) (Harbor dataset). You are in /app . Repair src/flood audit/audit.py so the CLI detects flood extent from paired before/after satellite image tiles.