Add AOI hotspot strict audit for 20nm compare

AGENTS.md

@@ -115,12 +115,18 @@ When changing the primary compare page:
 For the current 20nm visual baseline, prefer:
 
 - [`navsea_strict_audit.py`](/root/sourceserver/pbf/navsea_strict_audit.py)
+- [`strict_audit_hotspots_20nm.json`](/root/sourceserver/pbf/strict_audit_hotspots_20nm.json)
 
 This script combines:
 
 - browser-rendered screenshot diff from the fixed compare page
 - backend render audit summary from the current 20nm audit JSON
 
+And now focuses on:
+
+- small AOI hotspot crops that are chosen to calibrate backend audit blind spots
+- not just one coarse full-screen diff number
+
 Use it when you need one report that explains both:
 
 - what the user really sees