Harden campaign save timestamp recovery

src/game/state/campaignState.ts

@@ -831,7 +831,7 @@ function normalizeCampaignState(state: Partial<CampaignState>): CampaignState {
     ...cloneCampaignState(state as CampaignState)
   };
   normalized.version = 1;
-  normalized.updatedAt = typeof normalized.updatedAt === 'string' && normalized.updatedAt ? normalized.updatedAt : new Date().toISOString();
+  normalized.updatedAt = normalizeCampaignTimestamp(normalized.updatedAt) ?? new Date().toISOString();
   normalized.step = normalizeCampaignStep(normalized.step);
   normalized.activeSaveSlot = normalizeSlot(normalized.activeSaveSlot);
   normalized.gold = normalizeNonNegativeInteger(normalized.gold);
@@ -899,6 +899,23 @@ function normalizeNonNegativeInteger(value: unknown) {
   return Number.isFinite(numeric) && numeric > 0 ? numeric : 0;
 }
 
+function normalizeCampaignTimestamp(value: unknown) {
+  if (typeof value !== 'string' || value.length === 0) {
+    return undefined;
+  }
+
+  return campaignTimestampMs(value) === undefined ? undefined : value;
+}
+
+function campaignTimestampMs(value: unknown) {
+  if (typeof value !== 'string' || value.length === 0) {
+    return undefined;
+  }
+
+  const timestamp = Date.parse(value);
+  return Number.isFinite(timestamp) ? timestamp : undefined;
+}
+
 function normalizeInventory(value: unknown) {
   return Object.entries(recordOrEmpty(value)).reduce<Record<string, number>>((inventory, [itemId, amount]) => {
     const normalizedItemId = itemId.replace(/\s+/g, ' ').trim();
@@ -930,7 +947,7 @@ function normalizeLatestBattleId(value: unknown, battleHistory: Record<string, C
   }
 
   return Object.values(battleHistory)
-    .sort((a, b) => String(b.completedAt).localeCompare(String(a.completedAt)))[0]?.battleId;
+    .sort((a, b) => (campaignTimestampMs(b.completedAt) ?? 0) - (campaignTimestampMs(a.completedAt) ?? 0))[0]?.battleId;
 }
 
 function filterFirstBattleReportRosterReferences(report: FirstBattleReport, rosterUnitIds: Set<string>): FirstBattleReport {
@@ -951,14 +968,14 @@ function normalizeCampaignBattleSettlement(value: unknown): CampaignBattleSettle
 
   const settlement = value as Partial<CampaignBattleSettlement>;
   const battleId = typeof settlement.battleId === 'string' ? settlement.battleId : '';
+  const completedAt = normalizeCampaignTimestamp(settlement.completedAt);
   if (
     battleId.length === 0 ||
     !(battleId in battleScenarios) ||
     typeof settlement.battleTitle !== 'string' ||
     settlement.battleTitle.length === 0 ||
     (settlement.outcome !== 'victory' && settlement.outcome !== 'defeat') ||
-    typeof settlement.completedAt !== 'string' ||
-    settlement.completedAt.length === 0
+    !completedAt
   ) {
     return undefined;
   }
@@ -982,7 +999,7 @@ function normalizeCampaignBattleSettlement(value: unknown): CampaignBattleSettle
     reserveTraining: arrayOrEmpty<unknown>(settlement.reserveTraining)
       .map(normalizeReserveTrainingSnapshot)
       .filter((entry): entry is CampaignReserveTrainingSnapshot => Boolean(entry)),
-    completedAt: settlement.completedAt
+    completedAt
   };
 }
 
@@ -1154,7 +1171,7 @@ function normalizeFirstBattleReport(report: unknown): FirstBattleReport | undefi
     ),
     completedCampDialogues: uniqueStrings(report.completedCampDialogues),
     completedCampVisits: uniqueStrings(report.completedCampVisits),
-    createdAt: typeof report.createdAt === 'string' && report.createdAt.length > 0 ? report.createdAt : new Date().toISOString()
+    createdAt: normalizeCampaignTimestamp(report.createdAt) ?? new Date().toISOString()
   };
 }
 
@@ -1276,6 +1293,11 @@ function reserveTrainingFocusDefinition(focusId?: string) {
 }
 
 function readStoredCampaignState(slot?: number) {
+  const parsed = readStoredCampaignStateObject(slot);
+  return parsed ? normalizeCampaignState(parsed) : undefined;
+}
+
+function readStoredCampaignStateObject(slot?: number) {
   const raw = tryStorage()?.getItem(slot ? campaignSaveSlotKey(slot) : campaignStorageKey);
   if (!raw) {
     return undefined;
@@ -1289,7 +1311,7 @@ function readStoredCampaignState(slot?: number) {
     if (parsed.version !== undefined && parsed.version !== 1) {
       return undefined;
     }
-    return normalizeCampaignState(parsed);
+    return parsed;
   } catch {
     return undefined;
   }
@@ -1320,10 +1342,18 @@ function normalizeSlot(slot: number | undefined) {
 }
 
 function readLatestSlottedCampaignState() {
-  const latest = listCampaignSaveSlots()
-    .filter((slot) => slot.exists && slot.updatedAt)
-    .sort((a, b) => String(b.updatedAt).localeCompare(String(a.updatedAt)))[0];
-  return latest ? readStoredCampaignState(latest.slot) : undefined;
+  let latestSlot: number | undefined;
+  let latestUpdatedAt = Number.NEGATIVE_INFINITY;
+
+  for (let slot = 1; slot <= campaignSaveSlotCount; slot += 1) {
+    const timestamp = campaignTimestampMs(readStoredCampaignStateObject(slot)?.updatedAt);
+    if (timestamp !== undefined && timestamp > latestUpdatedAt) {
+      latestSlot = slot;
+      latestUpdatedAt = timestamp;
+    }
+  }
+
+  return latestSlot ? readStoredCampaignState(latestSlot) : undefined;
 }
 
 function advanceBond(bond: CampBondSnapshot, amount: number) {