refactor(frontend): major rebuild — feature-sliced architecture + bug fixes + glass-morphism UI

Architecture:
- Feature-sliced directory: entities/, shared/, features/, widgets/
- Consolidated API client (shared/api/client.ts) — all endpoints in one file
- Single WebSocket manager (shared/ws/socket.ts) with typed event bus
- Extracted hooks: useAudioPlayback, useAudioTransmit, useLocalStorage, useUIState
- UI primitives moved to shared/ui/ with barrel export
- Added Skeleton, Toast, MobileTabBar components

Bug fixes (8/8):
1. useMemo→useEffect in RecordingsSubPanel (async side-effect anti-pattern)
2. ArrayBuffer.slice() before WebSocket send (shared buffer bug)
3. Proper useEffect dependency arrays throughout
4. Stable React keys (no index fallbacks)
5. onReanalyze properly awaited (Promise<void> return)
6. monitorGuild memoized with useMemo
7. localStorage validation with shape checking
8. Deleted duplicate socket logic (ws/client.ts removed)

UI polish:
- Glass-morphism design tokens (backdrop-blur, translucent cards)
- Gradient mesh background with subtle radial overlays
- Expandable sidebar + mobile bottom tab bar
- Skeleton loading placeholders
- Audio visualizer with CSS pulse animation

Deleted: src/api/, src/components/, src/hooks/, src/types/, src/ws/, src/lib/
Added: 40 new files across feature-sliced structure

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/features/analytics/components/ViolatorTable.tsx

@@ -0,0 +1,130 @@
+import { Siren } from "lucide-react";
+import type { ViolatorStat } from "../../../shared/api/client";
+import { Badge, Card, CardContent, CardDescription, CardHeader, CardTitle, ScrollArea } from "../../../shared/ui";
+
+interface ViolatorTableProps {
+  users: ViolatorStat[];
+  loading: boolean;
+}
+
+export function ViolatorTable({ users, loading }: ViolatorTableProps) {
+  if (loading && !users?.length) {
+    return <LoadingBox />;
+  }
+
+  if (!users?.length) {
+    return (
+      <Card>
+        <CardContent className="flex h-[260px] items-center justify-center text-sm text-muted-foreground">
+          Tidak ada pelanggaran terdeteksi.
+        </CardContent>
+      </Card>
+    );
+  }
+
+  const maxScore = Math.max(...users.map((u) => u.violation_score), 1);
+
+  function dangerLabel(score: number) {
+    if (score >= 10) return { variant: "destructive" as const, text: "HIGH" };
+    if (score >= 5) return { variant: "warning" as const, text: "MED" };
+    return { variant: "secondary" as const, text: "LOW" };
+  }
+
+  return (
+    <Card>
+      <CardHeader className="pb-2">
+        <div className="flex items-center justify-between">
+          <div>
+            <CardTitle className="flex items-center gap-2 text-sm font-semibold">
+              <Siren className="h-4 w-4 text-red-400" />
+              Pelanggar Terbanyak
+            </CardTitle>
+            <CardDescription className="text-xs">
+              Skor: flagged × 3 + warned × 1.
+            </CardDescription>
+          </div>
+          <Badge variant="destructive">{users.length} pelanggar</Badge>
+        </div>
+      </CardHeader>
+      <CardContent className="p-0">
+        <ScrollArea className="max-h-[260px]">
+          <table className="w-full text-sm">
+            <thead>
+              <tr className="sticky top-0 z-10 bg-card/95 backdrop-blur border-b border-border text-left text-[10px] uppercase tracking-wider text-muted-foreground">
+                <th className="py-2 pl-4 pr-2 font-semibold">#</th>
+                <th className="py-2 pr-2 font-semibold">User</th>
+                <th className="py-2 pr-2 font-semibold text-right">Warned</th>
+                <th className="py-2 pr-2 font-semibold text-right">Flagged</th>
+                <th className="py-2 pr-4 font-semibold text-right">Skor</th>
+              </tr>
+            </thead>
+            <tbody className="divide-y divide-border/20">
+              {users.map((user, i) => {
+                const danger = dangerLabel(user.violation_score);
+                return (
+                  <tr key={user.user_id} className="hover:bg-red-500/5 transition-colors">
+                    <td className="py-1.5 pl-4 pr-2 font-mono text-[10px] text-muted-foreground tabular-nums">
+                      {i + 1}
+                    </td>
+                    <td className="py-1.5 pr-2">
+                      <div className="flex items-center gap-2">
+                        {user.avatar_url ? (
+                          <img src={user.avatar_url} alt="" className="h-6 w-6 rounded-full" loading="lazy" />
+                        ) : (
+                          <div className="flex h-6 w-6 items-center justify-center rounded-full bg-muted text-[10px] font-bold">
+                            {user.username.charAt(0).toUpperCase()}
+                          </div>
+                        )}
+                        <span className="max-w-[100px] truncate text-xs font-medium">{user.username}</span>
+                        <Badge variant={danger.variant} className="text-[9px] px-1 py-0">
+                          {danger.text}
+                        </Badge>
+                      </div>
+                    </td>
+                    <td className="py-1.5 pr-2 text-right font-mono text-xs text-amber-400 tabular-nums">
+                      {user.warned_count}
+                    </td>
+                    <td className="py-1.5 pr-2 text-right font-mono text-xs text-red-400 tabular-nums">
+                      {user.flagged_count}
+                    </td>
+                    <td className="py-1.5 pr-4 text-right">
+                      <div className="flex items-center justify-end gap-1.5">
+                        <div className="h-1.5 w-14 overflow-hidden rounded-full bg-muted">
+                          <div
+                            className={cn(
+                              "h-full rounded-full",
+                              user.violation_score >= 10
+                                ? "bg-gradient-to-r from-red-600 to-red-400"
+                                : user.violation_score >= 5
+                                  ? "bg-gradient-to-r from-amber-500 to-amber-400"
+                                  : "bg-gradient-to-r from-yellow-500 to-yellow-400",
+                            )}
+                            style={{ width: `${(user.violation_score / maxScore) * 100}%` }}
+                          />
+                        </div>
+                        <span className="font-mono text-xs font-bold tabular-nums">{user.violation_score}</span>
+                      </div>
+                    </td>
+                  </tr>
+                );
+              })}
+            </tbody>
+          </table>
+        </ScrollArea>
+      </CardContent>
+    </Card>
+  );
+}
+
+import { cn } from "../../../shared/lib/utils";
+
+function LoadingBox() {
+  return (
+    <Card>
+      <CardContent className="flex h-[260px] items-center justify-center text-sm text-muted-foreground">
+        <span className="h-4 w-4 animate-spin rounded-full border-2 border-current border-t-transparent" />
+        <span className="ml-2">Memuat data...</span>
+      </CardContent>
+    </Card>
+  );
+}