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

packages/request-handler/src/docker.ts

@@ -171,7 +171,6 @@ const mockContainers: {
 ];
 
 export const dockerContainersRequestHandler = createWidgetRequestHandler({
-  queryKey: "dockerContainersResult",
   async requestAsync() {
     if (isDemoMode) {
       return mockContainers;