feat(lotto): grade_tickets 매칭 채점 + 등수 매핑

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lotto/tests/test_backtest.py

@@ -0,0 +1,25 @@
+from app import backtest as bt
+from app.analyzer import build_analysis_cache, score_combination
+
+
+def test_grade_tickets_histogram_and_prizes():
+    winning6 = [1, 2, 3, 4, 5, 6]
+    bonus = 7
+    tickets = [
+        [1, 2, 3, 4, 5, 6],     # 6일치 = 1등
+        [1, 2, 3, 4, 5, 7],     # 5일치 + 보너스 = 2등
+        [1, 2, 3, 4, 5, 8],     # 5일치 = 3등
+        [1, 2, 3, 4, 9, 10],    # 4일치 = 4등
+        [1, 2, 3, 11, 12, 13],  # 3일치 = 5등
+        [40, 41, 42, 43, 44, 45],  # 0일치
+    ]
+    r = bt.grade_tickets(tickets, winning6, bonus)
+    assert r["m6"] == 1
+    assert r["m5"] == 2           # 5일치 총 2장(보너스 포함)
+    assert r["bonus_hits"] == 1   # 그 중 보너스 1장
+    assert r["m4"] == 1
+    assert r["m3"] == 1
+    assert r["best_match"] == 6
+    # 등수 매핑 헬퍼
+    prizes = bt.prize_counts(r)
+    assert prizes == {"1st": 1, "2nd": 1, "3rd": 1, "4th": 1, "5th": 1}