fix: address PR review — bugs, dead code, error handling

Critical fixes:
- Smart Home: invalidate entity state query after toggle mutation
- Beszel live mode: use 5s refetchInterval instead of global 30s
- Fix unit test assertions for 5-arg setQueryCacheAsync signature
- Fix serialize/deserialize mismatch: JSON.parse on read (matches persister's JSON.stringify)
- Remove render-time setActiveQueryCacheBoardId race (keep only useEffect)

Error handling:
- Log persistence errors instead of swallowing with catch(() => {})
- Log QueryCacheHydration failures with ErrorWithMetadata
- Beszel: log partial failures (system details, container stats)

Dead code removal:
- Remove dead queryKey from all 39 request handlers + lib files
- Delete unused Redis APIs: createCacheChannel, createChannelWithLatestAndEvents,
  createChannelEventHistory, history-channel.ts
- Remove stale createCacheChannel mock from docker test

Cleanup:
- Seed system-resources chart from initial query data (no empty start)
- Remove redundant refetchOnWindowFocus/refetchOnReconnect from BoardProvider

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

@@ -3,17 +3,22 @@ import { createAsyncStoragePersister } from "@tanstack/query-async-storage-persi
 import { fetchApi } from "@homarr/api/client";
 import { getActiveQueryCacheBoardId, queryCacheStoragePrefix } from "@homarr/api/query-cache";
 
+// ponytail: write-only persister — restore is SSR-only via QueryCacheHydration
 const queryCacheStorage = {
   getItem: (_key: string) => null as string | null,
   async setItem(_key: string, value: string) {
     const boardId = getActiveQueryCacheBoardId();
     if (!boardId) return;
-    await fetchApi.queryCache.setItem.mutate({ boardId, value }).catch(() => {});
+    await fetchApi.queryCache.setItem.mutate({ boardId, value }).catch((error) => {
+      console.warn("[query-cache] persist failed", error);
+    });
   },
   async removeItem(_key: string) {
     const boardId = getActiveQueryCacheBoardId();
     if (!boardId) return;
-    await fetchApi.queryCache.removeItem.mutate({ boardId }).catch(() => {});
+    await fetchApi.queryCache.removeItem.mutate({ boardId }).catch((error) => {
+      console.warn("[query-cache] remove failed", error);
+    });
   },
 };
 

apps/nextjs/src/app/[locale]/boards/(content)/_creator.tsx

@@ -7,8 +7,6 @@ import "~/styles/gridstack.scss";
 
 import { dehydrate, HydrationBoundary } from "@tanstack/react-query";
 import type { PersistedClient } from "@tanstack/react-query-persist-client";
-import { parse } from "superjson";
-
 import { getQueryClient } from "@homarr/api/server";
 import { IntegrationProvider } from "@homarr/auth/client";
 import { auth } from "@homarr/auth/next";
@@ -123,11 +121,14 @@ async function QueryCacheHydration({ userId, boardId }: { userId: string; boardI
     const serialized = await getQueryCacheAsync(userId, boardId);
     if (!serialized) return null;
 
-    const persisted = parse<PersistedClient>(serialized);
+    const persisted = JSON.parse(serialized) as PersistedClient;
     if (!persisted?.clientState?.queries?.length) return null;
 
     return <HydrationBoundary state={persisted.clientState} />;
-  } catch {
+  } catch (error) {
+    logger.warn(
+      new ErrorWithMetadata("Failed to hydrate query cache", { userId, boardId }, { cause: error }),
+    );
     return null;
   }
 }