fix(tests): fresh_db fixture가 매 test마다 db.DB_PATH 재패치 (cross-file isolation)

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

agent-office/tests/test_lotto_task_wrap.py

@@ -18,6 +18,8 @@ db.DB_PATH = _TMP
 
 @pytest.fixture(autouse=True)
 def fresh_db():
+    # Re-patch DB_PATH at the start of every test (cross-file isolation)
+    db.DB_PATH = _TMP
     gc.collect()
     if os.path.exists(_TMP):
         os.remove(_TMP)