refactor: split monolith into 3 microservices (frontend, backend, discord-gateway)

- Extract services into services/{frontend,backend,discord-gateway}
- Create packages/shared/ for shared logger, errors, utils, types
- Setup Modular MVC pattern in backend (controller→service→repository)
- Setup event-driven architecture in discord-gateway with Redis pub/sub
- Move Docker files to infra/docker/ with per-service Dockerfiles
- Update docker-compose.yml to use Traefik-only routing (no port exposes)
- Update GitHub Actions deploy workflow for multi-service matrix build
- Fix all import paths and resolve type errors across all services
- All 3 services pass tsc --noEmit clean

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

services/frontend/src/features/live/components/AudioVisualizer.tsx

@@ -0,0 +1,61 @@
+import { useEffect, useRef } from "react";
+
+interface AudioVisualizerProps {
+  levels: number[];
+}
+
+export function AudioVisualizer({ levels }: AudioVisualizerProps) {
+  const canvasRef = useRef<HTMLCanvasElement>(null);
+
+  useEffect(() => {
+    const canvas = canvasRef.current;
+    if (!canvas) return;
+    const ctx = canvas.getContext("2d");
+    if (!ctx) return;
+
+    const width = canvas.width;
+    const height = canvas.height;
+
+    ctx.clearRect(0, 0, width, height);
+
+    const barWidth = width / levels.length;
+    const maxBarHeight = height * 0.85;
+
+    for (let i = 0; i < levels.length; i++) {
+      const level = levels[i];
+      const barHeight = Math.min(maxBarHeight, level * maxBarHeight);
+      const x = i * barWidth;
+      const y = height - barHeight;
+
+      // Gradient color based on level
+      const hue = 199 - level * 199;
+      const saturation = 89;
+      const lightness = 48 + level * 20;
+      ctx.fillStyle = `hsl(${hue}, ${saturation}%, ${lightness}%)`;
+
+      // Rounded bar
+      const radius = barWidth * 0.3;
+      ctx.beginPath();
+      ctx.moveTo(x + radius, y);
+      ctx.lineTo(x + barWidth - radius, y);
+      ctx.quadraticCurveTo(x + barWidth, y, x + barWidth, y + radius);
+      ctx.lineTo(x + barWidth, height);
+      ctx.lineTo(x, height);
+      ctx.lineTo(x, y + radius);
+      ctx.quadraticCurveTo(x, y, x + radius, y);
+      ctx.fill();
+    }
+  }, [levels]);
+
+  return (
+    <div className="relative w-full">
+      <canvas
+        ref={canvasRef}
+        width={512}
+        height={128}
+        className="w-full rounded-xl bg-muted/30"
+        style={{ height: "128px" }}
+      />
+    </div>
+  );
+}