Normalize explicit campaign slot reads

scripts/verify-campaign-save-normalization.mjs

@@ -679,6 +679,33 @@ try {
   const fallback = loadCampaignState();
   assert(fallback.step === 'second-camp' && fallback.activeSaveSlot === 2, `Expected valid slotted save fallback: ${JSON.stringify(fallback)}`);
 
+  storage.clear();
+  storage.set(
+    campaignStorageKey,
+    JSON.stringify({
+      version: 1,
+      updatedAt: '2026-07-01T00:00:00.000Z',
+      step: 'first-camp',
+      activeSaveSlot: 1,
+      gold: 100
+    })
+  );
+  storage.set(
+    `${campaignStorageKey}:slot-1`,
+    JSON.stringify({
+      version: 1,
+      updatedAt: '2026-07-02T00:00:00.000Z',
+      step: 'second-camp',
+      activeSaveSlot: 1,
+      gold: 200
+    })
+  );
+  const normalizedSlotFallback = loadCampaignState(0);
+  assert(
+    normalizedSlotFallback.step === 'second-camp' && normalizedSlotFallback.gold === 200,
+    `Expected explicit slot boundary values to normalize to slot 1 instead of base save: ${JSON.stringify(normalizedSlotFallback)}`
+  );
+
   storage.clear();
   storage.set(campaignStorageKey, JSON.stringify({ version: 99, step: 'sixty-sixth-camp' }));
   storage.set(

src/game/state/campaignState.ts

@@ -1298,7 +1298,7 @@ function readStoredCampaignState(slot?: number) {
 }
 
 function readStoredCampaignStateObject(slot?: number) {
-  const raw = tryStorage()?.getItem(slot ? campaignSaveSlotKey(slot) : campaignStorageKey);
+  const raw = tryStorage()?.getItem(slot === undefined ? campaignStorageKey : campaignSaveSlotKey(slot));
   if (!raw) {
     return undefined;
   }