Harden battle save growth validation

src/game/state/battleSaveState.ts

@@ -1,7 +1,7 @@
 import type { BattleBond, UnitData } from '../data/scenario';
 import type { CampaignStep } from './campaignState';
 import type { UnitDirection } from '../data/unitAssets';
-import { equipmentSlots, type EquipmentSlot } from '../data/battleItems';
+import { equipmentExpToNext, equipmentSlots, type EquipmentSlot } from '../data/battleItems';
 
 export type BattleSaveFaction = 'ally' | 'enemy';
 export type BattleSaveRosterTab = 'ally' | 'enemy';
@@ -239,8 +239,7 @@ function isSavedBattleUnitState(value: unknown, options: BattleSaveValidationOpt
   }
 
   if (
-    !isPositiveInteger(value.level) ||
-    !isNonNegativeFiniteNumber(value.exp) ||
+    !isValidCharacterProgress(value.level, value.exp) ||
     !isNonNegativeFiniteNumber(value.hp) ||
     !isPositiveInteger(value.maxHp) ||
     Number(value.hp) > Number(value.maxHp) ||
@@ -282,11 +281,28 @@ function isEquipmentStateForSlot(value: unknown, slot: EquipmentSlot, options: B
     itemId.length > 0 &&
     (!options.validEquipmentItemIds || options.validEquipmentItemIds.has(itemId)) &&
     (!options.validEquipmentSlotItems?.[slot] || options.validEquipmentSlotItems[slot].has(itemId)) &&
-    isPositiveInteger(level) &&
-    isNonNegativeFiniteNumber(exp)
+    isValidEquipmentProgress(level, exp)
   );
 }
 
+function isValidCharacterProgress(level: unknown, exp: unknown) {
+  return (
+    isPositiveInteger(level) &&
+    Number.isInteger(exp) &&
+    Number(exp) >= 0 &&
+    (Number(level) >= 99 ? Number(exp) <= 100 : Number(exp) < 100)
+  );
+}
+
+function isValidEquipmentProgress(level: unknown, exp: unknown) {
+  if (!Number.isInteger(level) || Number(level) < 1 || Number(level) > 9 || !Number.isInteger(exp) || Number(exp) < 0) {
+    return false;
+  }
+
+  const next = equipmentExpToNext(Number(level));
+  return Number(level) >= 9 ? Number(exp) <= next : Number(exp) < next;
+}
+
 function isBondArray(value: unknown, options: BattleSaveValidationOptions) {
   return (
     Array.isArray(value) &&