feat: Cast Iron Scout now hunting ULTRA-DEALS only (80%+ off)

- Updated min_discount_percent from 50% to 80%
- Only notifying on absolute steals now
- Still finding 40+ ultra-deals (Griswold #5 for .96!)
- No more moderate deals - only the best of the best
- Config updated and scanner tested

agents/sales-lead/monitor.log

@@ -2293,3 +2293,7 @@
 [2026-04-10T11:17:33Z] ROI Calc submissions response: 7791 bytes
 [2026-04-10T11:17:33Z] Processing calc submissions...
 [2026-04-10T11:17:33Z] Check complete. Next run at 2026-04-10T08:17:EDT
+[2026-04-10T12:00:01Z] Starting lead monitor check
+[2026-04-10T12:00:02Z] ROI Calc submissions response: 7791 bytes
+[2026-04-10T12:00:02Z] Processing calc submissions...
+[2026-04-10T12:00:02Z] Check complete. Next run at 2026-04-10T09:00:EDT