feat(engine): add action queue state and enqueue APIs

src/state/__tests__/persistence.test.ts

@@ -46,7 +46,12 @@ describe('loadGame()', () => {
     const content = testContent();
     const stale = serializeSave(
       createSave(
-        { resources: { gold: 1 }, activeActionId: 'ghost-action', actionElapsedMs: 0 },
+        {
+          resources: { gold: 1 },
+          activeActionId: 'ghost-action',
+          actionElapsedMs: 0,
+          actionQueue: [],
+        },
         1000,
       ),
     );

src/state/persistence.ts

@@ -102,6 +102,7 @@ export async function loadGame(
       resources: { ...base.resources, ...save.state.resources },
       activeActionId,
       actionElapsedMs: save.state.actionElapsedMs,
+      actionQueue: [...base.actionQueue],
     };
     savedAt = save.savedAt;
   } catch {