feat: 스튜디오 페이지 + Suno API 프록시 + 팩 상세 가격 최상단 재구성

- TopNav: 홈/샘플/팩 상세/스튜디오 4개 링크 구조
- /services/music: 컴팩트 헤더 + PRICING 최상단 배치 (상세 포맷)
- /studio: Suno Generate UI (simple/custom 모드, 태그 프리셋, 폴링)
- /api/studio/generate, /api/studio/status: Suno API 프록시

app/api/studio/generate/route.ts

@@ -0,0 +1,76 @@
+import { NextResponse } from 'next/server';
+
+export const runtime = 'nodejs';
+
+type GenerateBody = {
+  mode: 'simple' | 'custom';
+  prompt?: string;
+  title?: string;
+  lyrics?: string;
+  tags?: string;
+  make_instrumental?: boolean;
+  model?: string;
+};
+
+export async function POST(request: Request) {
+  const apiUrl = process.env.SUNO_API_URL;
+  const apiKey = process.env.SUNO_API_KEY;
+
+  if (!apiUrl || !apiKey) {
+    return NextResponse.json(
+      { error: 'Suno API 미설정 (SUNO_API_URL / SUNO_API_KEY 환경변수 필요)' },
+      { status: 503 },
+    );
+  }
+
+  let body: GenerateBody;
+  try {
+    body = (await request.json()) as GenerateBody;
+  } catch {
+    return NextResponse.json({ error: 'Invalid JSON' }, { status: 400 });
+  }
+
+  const endpoint = body.mode === 'custom' ? '/api/custom_generate' : '/api/generate';
+
+  const payload =
+    body.mode === 'custom'
+      ? {
+          prompt: body.lyrics ?? '',
+          tags: body.tags ?? '',
+          title: body.title ?? '',
+          make_instrumental: !!body.make_instrumental,
+          model: body.model ?? 'chirp-v3-5',
+          wait_audio: false,
+        }
+      : {
+          prompt: body.prompt ?? '',
+          make_instrumental: !!body.make_instrumental,
+          model: body.model ?? 'chirp-v3-5',
+          wait_audio: false,
+        };
+
+  try {
+    const res = await fetch(`${apiUrl.replace(/\/$/, '')}${endpoint}`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${apiKey}`,
+      },
+      body: JSON.stringify(payload),
+    });
+
+    const data = await res.json().catch(() => null);
+    if (!res.ok) {
+      return NextResponse.json(
+        { error: '생성 실패', detail: data ?? (await res.text().catch(() => '')) },
+        { status: res.status },
+      );
+    }
+    return NextResponse.json({ ok: true, data });
+  } catch (e) {
+    return NextResponse.json(
+      { error: 'Suno API 호출 오류', detail: e instanceof Error ? e.message : String(e) },
+      { status: 502 },
+    );
+  }
+}