fix: purchase/analysis API를 NAS → Supabase로 재설계

- 원인: purchase/personal은 유저별 데이터인데 NAS로 프록시 → NAS가 userId 모름
- ConnectTimeoutError는 NAS에 미구현 엔드포인트로 연결 시도한 결과

purchase/route.ts: nasGet/nasPost → Supabase lotto_purchases CRUD
purchase/stats/route.ts: nasGet → Supabase 집계 (총구매/당첨금/순손익 계산)
purchase/[id]/route.ts: nasPut/nasDelete → Supabase UPDATE/DELETE (user_id RLS)
analysis/personal/route.ts: nasGet → lotto_history 테이블 직접 분석
  (번호 빈도, top/least picks, 홀짝패턴, 구간 분포, 당첨평균 대비)

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

app/api/lotto/purchase/stats/route.ts

@@ -1,11 +1,37 @@
 import { NextResponse } from 'next/server';
-import { nasGet, requireSubscription, handleNasError } from '../../_nas';
+import { createClient } from '@/lib/supabase/server';
+import { requireSubscription } from '../../_nas';
 
 export async function GET() {
   try {
     const auth = await requireSubscription();
     if (auth instanceof NextResponse) return auth;
-    const data = await nasGet('/api/lotto/purchase/stats');
-    return NextResponse.json(data);
-  } catch (err) { return handleNasError(err); }
+
+    const supabase = await createClient();
+    const { data, error } = await supabase
+      .from('lotto_purchases')
+      .select('amount, prize')
+      .eq('user_id', auth.userId);
+
+    if (error) throw error;
+
+    const records = data ?? [];
+    const total_invested = records.reduce((s, r) => s + (r.amount ?? 0), 0);
+    const total_prize = records.reduce((s, r) => s + (r.prize ?? 0), 0);
+    const prize_count = records.filter(r => (r.prize ?? 0) > 0).length;
+    const max_prize = records.reduce((m, r) => Math.max(m, r.prize ?? 0), 0);
+
+    return NextResponse.json({
+      total_records: records.length,
+      total_invested,
+      total_prize,
+      net: total_prize - total_invested,
+      return_rate: total_invested > 0 ? Math.round((total_prize / total_invested) * 1000) / 10 : 0,
+      prize_count,
+      max_prize,
+    });
+  } catch (err) {
+    console.error('[purchase/stats]', err);
+    return NextResponse.json({ error: 'DB_ERROR' }, { status: 500 });
+  }
 }