feat: 관리자 패널 방문자 분석 페이지 추가 (GA4 Data API 연동)

- /admin/analytics 페이지 신규 추가
  - 일별 방문자 추이 바 차트 (7일/30일/90일 전환)
  - 오늘/이번주/기간별 요약 카드
  - 유입 경로 (채널별 비율 바)
  - 기기 유형 분포 (PC/모바일/태블릿)
  - 상위 페이지 조회수
- GET /api/admin/analytics 라우트 신규 추가 (@google-analytics/data)
- 사이드바에 방문자 분석 메뉴 추가
- 카페24 리뉴얼 견적 비교 SVG 에셋 추가 (public/marketing/quote-cafe24.svg)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/admin/analytics/route.ts

@@ -0,0 +1,137 @@
+import { NextResponse } from 'next/server';
+import { cookies } from 'next/headers';
+import { verifyAdminTokenNode } from '@/lib/admin-auth';
+import { BetaAnalyticsDataClient } from '@google-analytics/data';
+
+export const runtime = 'nodejs';
+
+function getClient() {
+  const raw = process.env.GOOGLE_SERVICE_ACCOUNT_JSON;
+  if (!raw) throw new Error('GOOGLE_SERVICE_ACCOUNT_JSON 환경변수가 설정되지 않았습니다.');
+  const credentials = JSON.parse(raw);
+  return new BetaAnalyticsDataClient({ credentials });
+}
+
+function getPropertyId() {
+  const id = process.env.GA4_PROPERTY_ID;
+  if (!id) throw new Error('GA4_PROPERTY_ID 환경변수가 설정되지 않았습니다.');
+  return id;
+}
+
+export async function GET(request: Request) {
+  // 관리자 인증
+  const cookieStore = await cookies();
+  const token = cookieStore.get('admin_token')?.value;
+  if (!token || !verifyAdminTokenNode(token)) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const { searchParams } = new URL(request.url);
+  const range = searchParams.get('range') ?? '30'; // 7, 30, 90
+  const days = parseInt(range);
+
+  try {
+    const client = getClient();
+    const propertyId = getPropertyId();
+
+    const startDate = `${days}daysAgo`;
+
+    // 병렬로 3개 리포트 요청
+    const [trendRes, pagesRes, sourcesRes] = await Promise.all([
+      // 1. 일별 방문자 추이
+      client.runReport({
+        property: `properties/${propertyId}`,
+        dateRanges: [{ startDate, endDate: 'today' }],
+        dimensions: [{ name: 'date' }],
+        metrics: [{ name: 'activeUsers' }, { name: 'sessions' }, { name: 'screenPageViews' }],
+        orderBys: [{ dimension: { dimensionName: 'date' }, desc: false }],
+      }),
+
+      // 2. 상위 페이지
+      client.runReport({
+        property: `properties/${propertyId}`,
+        dateRanges: [{ startDate, endDate: 'today' }],
+        dimensions: [{ name: 'pagePath' }],
+        metrics: [{ name: 'screenPageViews' }, { name: 'activeUsers' }],
+        orderBys: [{ metric: { metricName: 'screenPageViews' }, desc: true }],
+        limit: 10,
+      }),
+
+      // 3. 유입 경로 + 기기
+      client.runReport({
+        property: `properties/${propertyId}`,
+        dateRanges: [{ startDate, endDate: 'today' }],
+        dimensions: [{ name: 'sessionDefaultChannelGroup' }, { name: 'deviceCategory' }],
+        metrics: [{ name: 'sessions' }, { name: 'activeUsers' }],
+        orderBys: [{ metric: { metricName: 'sessions' }, desc: true }],
+        limit: 20,
+      }),
+    ]);
+
+    // 오늘 / 어제 / 이번 주 / 기간 합계
+    const summaryRes = await client.runReport({
+      property: `properties/${propertyId}`,
+      dateRanges: [
+        { startDate: 'today', endDate: 'today' },
+        { startDate: 'yesterday', endDate: 'yesterday' },
+        { startDate: '7daysAgo', endDate: 'today' },
+        { startDate: startDate, endDate: 'today' },
+      ],
+      metrics: [{ name: 'activeUsers' }, { name: 'sessions' }, { name: 'screenPageViews' }],
+    });
+
+    // --- 파싱 ---
+    const summary = {
+      today: { users: 0, sessions: 0, pageviews: 0 },
+      yesterday: { users: 0, sessions: 0, pageviews: 0 },
+      week: { users: 0, sessions: 0, pageviews: 0 },
+      period: { users: 0, sessions: 0, pageviews: 0 },
+    };
+    const keys = ['today', 'yesterday', 'week', 'period'] as const;
+    summaryRes[0].rows?.forEach((row, i) => {
+      const key = keys[i];
+      if (key) {
+        summary[key] = {
+          users: parseInt(row.metricValues?.[0]?.value ?? '0'),
+          sessions: parseInt(row.metricValues?.[1]?.value ?? '0'),
+          pageviews: parseInt(row.metricValues?.[2]?.value ?? '0'),
+        };
+      }
+    });
+
+    const daily = (trendRes[0].rows ?? []).map((row) => ({
+      date: row.dimensionValues?.[0]?.value ?? '',
+      users: parseInt(row.metricValues?.[0]?.value ?? '0'),
+      sessions: parseInt(row.metricValues?.[1]?.value ?? '0'),
+      pageviews: parseInt(row.metricValues?.[2]?.value ?? '0'),
+    }));
+
+    const topPages = (pagesRes[0].rows ?? []).map((row) => ({
+      page: row.dimensionValues?.[0]?.value ?? '',
+      views: parseInt(row.metricValues?.[0]?.value ?? '0'),
+      users: parseInt(row.metricValues?.[1]?.value ?? '0'),
+    }));
+
+    // 채널별 집계
+    const channelMap: Record<string, number> = {};
+    const deviceMap: Record<string, number> = {};
+    (sourcesRes[0].rows ?? []).forEach((row) => {
+      const channel = row.dimensionValues?.[0]?.value ?? 'Unknown';
+      const device = row.dimensionValues?.[1]?.value ?? 'Unknown';
+      const sessions = parseInt(row.metricValues?.[0]?.value ?? '0');
+      channelMap[channel] = (channelMap[channel] ?? 0) + sessions;
+      deviceMap[device] = (deviceMap[device] ?? 0) + sessions;
+    });
+    const sources = Object.entries(channelMap)
+      .map(([channel, sessions]) => ({ channel, sessions }))
+      .sort((a, b) => b.sessions - a.sessions);
+    const devices = Object.entries(deviceMap)
+      .map(([device, sessions]) => ({ device, sessions }))
+      .sort((a, b) => b.sessions - a.sessions);
+
+    return NextResponse.json({ summary, daily, topPages, sources, devices });
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : '알 수 없는 오류';
+    return NextResponse.json({ error: msg }, { status: 500 });
+  }
+}