feat: write timestamped blocklist change reports on firewall sync

README.md

@@ -204,6 +204,11 @@ time and is never trimmed automatically.
   (`/blocklist` → remove) or directly on the router; the automated sync will
   not re-add entries that are not part of a scan.
 
+Each consolidated scan with `--update-firewall` also writes a timestamped
+change report to `reports/app/YYYY-MM-DD-hh-mm-ss.json`: the number and list
+of entries added / removed (complete-set delta), the full cumulative blocked
+list, and the router sync changes.
+
 ## Web UI
 
 `python app.py` starts a **localhost-only** Flask web UI (default