fix: defensive hardening — NaN guards, cast loop safety, discipline reset on new loop, spire mode maxFloorReached fix

src/lib/game/utils/combat-utils.ts

@@ -186,6 +186,9 @@ export function calcDamage(
     damage *= critDamageMult;
   }
 
+  // Final NaN guard — if anything produced NaN, return a safe fallback
+  if (!Number.isFinite(damage)) return 5;
+
   return damage;
 }