- scraper_stats.py: respect DATA_DIR env var when writing stats_*.json files
- generate_status.py: read stats files and write history from DATA_DIR instead of HERE
- build/Dockerfile: set DATA_DIR=/app/data as default env var
- docs/validation.md: end-to-end Docker validation recipe
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>