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/app/(dashboard)/voice/page.tsx

@@ -1,12 +1,11 @@
 "use client";
 
 import { useCallback, useEffect, useState } from "react";
-import { VoiceConnectionCard } from "@/components/voice/connection-card";
-import { SpeakerWaveform } from "@/components/voice/speaker-waveform";
-import { MicControl } from "@/components/voice/mic-control";
-import { VoiceActivityTimeline } from "@/components/voice/activity-timeline";
 import { SubNav } from "@/components/layout/sub-nav";
-import { useWebSocket } from "@/lib/ws/context";
+import { VoiceActivityTimeline } from "@/components/voice/activity-timeline";
+import { VoiceConnectionCard } from "@/components/voice/connection-card";
+import { MicControl } from "@/components/voice/mic-control";
+import { SpeakerWaveform } from "@/components/voice/speaker-waveform";
 import {
   useGuilds,
   useMicTransmit,
@@ -16,6 +15,7 @@ import {
   useVoiceDisconnect,
   useVoiceStatus,
 } from "@/hooks";
+import { useWebSocket } from "@/lib/ws/context";
 
 type VoiceTab = "connection" | "activity";
 
@@ -83,7 +83,12 @@ export default function VoicePage() {
         selectedChannel={selectedChannel}
         onGuildChange={handleGuildChange}
         onChannelChange={(v) => setSelectedChannel(v ?? "")}
-        onConnect={() => connectMut.mutate({ guildId: selectedGuild, channelId: selectedChannel })}
+        onConnect={() =>
+          connectMut.mutate({
+            guildId: selectedGuild,
+            channelId: selectedChannel,
+          })
+        }
         onDisconnect={() => disconnectMut.mutate(undefined)}
         connecting={connectMut.isPending}
       />