Require valid campaign save for continue

src/game/state/campaignState.ts

@@ -568,7 +568,7 @@ export function resetCampaignState() {
 }
 
 export function hasCampaignSave() {
-  return Boolean(tryStorage()?.getItem(campaignStorageKey) ?? readLatestSlottedCampaignState());
+  return Boolean(readStoredCampaignState() ?? readLatestSlottedCampaignState());
 }
 
 export function listCampaignSaveSlots(): CampaignSaveSlotSummary[] {