refactor(fe): replace TanStack Query with SWR + UI/data cleanup

Rombak data layer frontend:
- Hapus @tanstack/react-query (package.json, lockfile, provider di
  dashboard layout) — ganti SWR 2.4.2 + SWRConfig (revalidateOnFocus
  false, deduping 10s, no retry on 404)
- Semua hooks data ditulis ulang ke useSWR; useAction() helper baru
  pengganti useMutation dengan surface kompatibel (mutate/mutateAsync/
  isPending/error)
- useMessages + useMessagesHasMore share satu SWR key — probe cursor
  yang tadinya dobel fetch API sekarang deduped
- WS sync (messages/media/recordings) pindah dari queryClient ke
  SWR mutate dengan filter key + revalidate:false
- useMessageSearch() dipakai search-panel & search-overlay; search
  overlay backdrop div -> button (fix a11y lint)

Rapikan UI + isi data:
- Tab stats recordings: placeholder 'coming soon' diganti stat asli
  (total, ukuran, speaker unik, top speakers)
- Empty states konsisten via EmptyState (images/review/recordings),
  EmptyState terima className
- biome check --write: 0 error, 8 warning pre-existing
- Verifikasi: tsc --noEmit PASS, next build PASS (11 halaman static),
  API live dicek — semua endpoint dashboard/messages/guilds/config/
  voice/media/recordings/review balikin data

services/frontend/src/hooks/use-guilds.ts

@@ -1,4 +1,4 @@
-import { useQuery } from "@tanstack/react-query";
+import useSWR from "swr";
 
 import { voiceApi } from "@/lib/api";
 import type { Guild } from "@/lib/types";
@@ -7,9 +7,7 @@ import type { Guild } from "@/lib/types";
  * Fetch the list of available Discord guilds.
  */
 export function useGuilds() {
-  return useQuery<Guild[]>({
-    queryKey: ["guilds"],
-    queryFn: () => voiceApi.getGuilds(),
-    staleTime: 60_000,
+  return useSWR<Guild[]>(["guilds"], () => voiceApi.getGuilds(), {
+    dedupingInterval: 60_000,
   });
 }