fix: normalize restored dashboard state

apps/nextjs/src/app/[locale]/_client-providers/query-persistence.spec.ts

@@ -72,6 +72,11 @@ describe("dashboard query persistence", () => {
     const { queryClient } = createSuccessfulQuery([["widget", "calendar", "findAllEvents"], { type: "query" }], {
       startsAt: new Date("2026-08-22T12:00:00.000Z"),
     });
+    const cachedQuery = queryClient.getQueryCache().find({
+      queryKey: [["widget", "calendar", "findAllEvents"], { type: "query" }],
+    });
+    if (!cachedQuery) throw new Error("Expected cached query to be present");
+    cachedQuery.setState({ ...cachedQuery.state, error: new Error("refresh failed"), status: "error" });
     queryClient.getMutationCache().build(
       queryClient,
       { mutationKey: ["integration", "create"], mutationFn: async () => undefined },
@@ -102,6 +107,8 @@ describe("dashboard query persistence", () => {
     expect(restored?.clientState.queries[0]?.state.data).toEqual({
       startsAt: new Date("2026-08-22T12:00:00.000Z"),
     });
+    expect(restored?.clientState.queries[0]?.state.status).toBe("success");
+    expect(restored?.clientState.queries[0]?.state.error).toBeNull();
     expect(await userB.persister.restoreClient()).toBeUndefined();
 
     await userA.persister.removeClient();
@@ -109,11 +116,16 @@ describe("dashboard query persistence", () => {
   });
 
   test("treats unavailable session storage as an empty cache", async () => {
-    vi.spyOn(window, "sessionStorage", "get").mockImplementation(() => {
+    const blockedStorage = createMemoryStorage();
+    blockedStorage.getItem = () => {
       throw new DOMException("blocked", "SecurityError");
-    });
+    };
+    blockedStorage.removeItem = () => {
+      throw new DOMException("blocked", "SecurityError");
+    };
 
-    const persistence = createSessionQueryPersistence("blocked");
+    const persistence = createSessionQueryPersistence("blocked", blockedStorage);
     expect(await persistence.persister.restoreClient()).toBeUndefined();
+    expect(() => persistence.persister.removeClient()).not.toThrow();
   });
 });

apps/nextjs/src/app/[locale]/_client-providers/query-persistence.ts

@@ -1,7 +1,7 @@
 import type { QueryKey } from "@tanstack/react-query";
 import { createSyncStoragePersister } from "@tanstack/query-sync-storage-persister";
 import { removeOldestQuery } from "@tanstack/react-query-persist-client";
-import type { PersistQueryClientProviderProps } from "@tanstack/react-query-persist-client";
+import type { PersistedClient, PersistQueryClientProviderProps } from "@tanstack/react-query-persist-client";
 import { parse, stringify } from "superjson";
 
 import { isPersistableDashboardQueryKey, queryCacheDefaultGcTimeMs } from "@homarr/api/query-cache";
@@ -21,6 +21,26 @@ interface PersistableQuery {
 export const shouldPersistDashboardQuery = (query: PersistableQuery) =>
   query.state.data !== undefined && isPersistableDashboardQueryKey(query.queryKey);
 
+const serializePersistedClient = (client: PersistedClient) =>
+  stringify({
+    ...client,
+    clientState: {
+      ...client.clientState,
+      queries: client.clientState.queries.map((query) => ({
+        ...query,
+        state: {
+          ...query.state,
+          error: null,
+          errorUpdateCount: 0,
+          errorUpdatedAt: 0,
+          fetchFailureCount: 0,
+          fetchFailureReason: null,
+          status: "success",
+        },
+      })),
+    },
+  });
+
 const getSessionStorage = () => {
   if (typeof window === "undefined") return undefined;
 
@@ -31,6 +51,30 @@ const getSessionStorage = () => {
   }
 };
 
+const protectStorage = (storage: Storage | undefined) => {
+  if (!storage) return undefined;
+
+  return {
+    getItem(key: string) {
+      try {
+        return storage.getItem(key);
+      } catch {
+        return null;
+      }
+    },
+    setItem(key: string, value: string) {
+      storage.setItem(key, value);
+    },
+    removeItem(key: string) {
+      try {
+        storage.removeItem(key);
+      } catch {
+        return undefined;
+      }
+    },
+  };
+};
+
 export type SessionQueryPersistence = PersistQueryClientProviderProps["persistOptions"];
 
 export const createSessionQueryPersistence = (
@@ -38,9 +82,9 @@ export const createSessionQueryPersistence = (
   storage: Storage | undefined = getSessionStorage(),
 ): SessionQueryPersistence => ({
   persister: createSyncStoragePersister({
-    storage,
+    storage: protectStorage(storage),
     key: getQueryPersistenceStorageKey(scope),
-    serialize: stringify,
+    serialize: serializePersistedClient,
     deserialize: parse,
     retry: removeOldestQuery,
   }),