fix(game): recover realtime dashboard delta cloning

app/game-frontend/src/utils/readModelDeltaRecovery.ts

@@ -0,0 +1,21 @@
+/**
+ * Resolves one delta response and retries once with a full snapshot when the
+ * client baseline cannot be reconstructed. The retry intentionally covers all
+ * local application failures, including browser DataCloneError variants.
+ */
+export const resolveWithReadModelSnapshotFallback = async <Response, Result>(options: {
+    request: (forceSnapshot: boolean) => Promise<Response>;
+    resolve: (response: Response) => Result;
+    forceSnapshot?: boolean;
+}): Promise<Result> => {
+    const forceSnapshot = options.forceSnapshot === true;
+    const response = await options.request(forceSnapshot);
+    try {
+        return options.resolve(response);
+    } catch (error) {
+        if (forceSnapshot) {
+            throw error;
+        }
+        return options.resolve(await options.request(true));
+    }
+};