v1.7.3

Features

• THRESHOLD_FALLBACK env var sets a separate confidence threshold for whole-image fallback classifications (when YOLO finds no animal to crop), instead of sharing THRESHOLD with real crops. Defaults to THRESHOLD's value, so it's a no-op unless set explicitly. The tagging accuracy tool has consistently measured the fallback path as a meaningfully noisier signal than a real crop; this lets that be corrected for in live tagging (e.g. setting it higher than THRESHOLD) instead of only being visible in the diagnostic.