feat: include current holdings in realtime trading loop for exit evaluation (#165)

스캐너 후보 종목뿐 아니라 현재 보유 종목도 매 사이클마다 평가해
stop-loss / take-profit이 실제로 동작하도록 개선.

- db.py: get_open_positions_by_market() 추가
  - net BUY - SELL 집계 쿼리로 실제 보유 종목 코드 목록 반환
  - 단순 "최신 레코드 = BUY" 방식보다 안전 (이중 매도 방지)
- main.py: 실시간 루프에서 스캐너 후보 + 보유 종목을 union으로 구성
  - dict.fromkeys로 순서 유지하며 중복 제거
  - 스캐너에 없는 보유 종목은 로그로 명시
  - 보유 종목은 Playbook 없으면 HOLD → stop-loss/take-profit 체크
- tests/test_db.py: get_open_positions_by_market 테스트 5개 추가
  - net 양수 종목 포함, 전량 매도 제외, 부분 매도 포함
  - 마켓 범위 격리, 거래 없을 때 빈 리스트

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

tests/test_db.py

@@ -1,6 +1,6 @@
 """Tests for database helper functions."""
 
-from src.db import get_open_position, init_db, log_trade
+from src.db import get_open_position, get_open_positions_by_market, init_db, log_trade
 
 
 def test_get_open_position_returns_latest_buy() -> None:
@@ -58,3 +58,87 @@ def test_get_open_position_returns_none_when_latest_is_sell() -> None:
 def test_get_open_position_returns_none_when_no_trades() -> None:
     conn = init_db(":memory:")
     assert get_open_position(conn, "AAPL", "US_NASDAQ") is None
+
+
+# --- get_open_positions_by_market tests ---
+
+
+def test_get_open_positions_by_market_returns_net_positive_stocks() -> None:
+    """Stocks with net BUY quantity > 0 are included."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn, stock_code="005930", action="BUY", confidence=90,
+        rationale="entry", quantity=5, price=70000.0, market="KR",
+        exchange_code="KRX", decision_id="d1",
+    )
+    log_trade(
+        conn=conn, stock_code="000660", action="BUY", confidence=85,
+        rationale="entry", quantity=3, price=100000.0, market="KR",
+        exchange_code="KRX", decision_id="d2",
+    )
+
+    result = get_open_positions_by_market(conn, "KR")
+    assert set(result) == {"005930", "000660"}
+
+
+def test_get_open_positions_by_market_excludes_fully_sold_stocks() -> None:
+    """Stocks where BUY qty == SELL qty are excluded (net qty = 0)."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn, stock_code="005930", action="BUY", confidence=90,
+        rationale="entry", quantity=3, price=70000.0, market="KR",
+        exchange_code="KRX", decision_id="d1",
+    )
+    log_trade(
+        conn=conn, stock_code="005930", action="SELL", confidence=95,
+        rationale="exit", quantity=3, price=71000.0, market="KR",
+        exchange_code="KRX", decision_id="d2",
+    )
+
+    result = get_open_positions_by_market(conn, "KR")
+    assert "005930" not in result
+
+
+def test_get_open_positions_by_market_includes_partially_sold_stocks() -> None:
+    """Stocks with partial SELL (net qty > 0) are still included."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn, stock_code="005930", action="BUY", confidence=90,
+        rationale="entry", quantity=5, price=70000.0, market="KR",
+        exchange_code="KRX", decision_id="d1",
+    )
+    log_trade(
+        conn=conn, stock_code="005930", action="SELL", confidence=95,
+        rationale="partial exit", quantity=2, price=71000.0, market="KR",
+        exchange_code="KRX", decision_id="d2",
+    )
+
+    result = get_open_positions_by_market(conn, "KR")
+    assert "005930" in result
+
+
+def test_get_open_positions_by_market_is_market_scoped() -> None:
+    """Only stocks from the specified market are returned."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn, stock_code="005930", action="BUY", confidence=90,
+        rationale="entry", quantity=3, price=70000.0, market="KR",
+        exchange_code="KRX", decision_id="d1",
+    )
+    log_trade(
+        conn=conn, stock_code="AAPL", action="BUY", confidence=85,
+        rationale="entry", quantity=2, price=200.0, market="NASD",
+        exchange_code="NAS", decision_id="d2",
+    )
+
+    kr_result = get_open_positions_by_market(conn, "KR")
+    nasd_result = get_open_positions_by_market(conn, "NASD")
+
+    assert kr_result == ["005930"]
+    assert nasd_result == ["AAPL"]
+
+
+def test_get_open_positions_by_market_returns_empty_when_no_trades() -> None:
+    """Empty list returned when no trades exist for the market."""
+    conn = init_db(":memory:")
+    assert get_open_positions_by_market(conn, "KR") == []