feat: trades 테이블 mode 컬럼 추가 (paper/live 거래 분리) (#212)

- trades 테이블에 mode TEXT DEFAULT 'paper' 컬럼 추가
- 기존 DB 마이그레이션: ALTER TABLE으로 mode 컬럼 자동 추가
- log_trade() 함수에 mode 파라미터 추가 (기본값 'paper')
- trading_cycle(), run_daily_session()에서 settings.MODE 전달
- 테스트 5개 추가 (mode 저장, 기본값, 스키마 검증, 마이그레이션)

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

src/db.py

@@ -28,12 +28,13 @@ def init_db(db_path: str) -> sqlite3.Connection:
             pnl REAL DEFAULT 0.0,
             market TEXT DEFAULT 'KR',
             exchange_code TEXT DEFAULT 'KRX',
-            decision_id TEXT
+            decision_id TEXT,
+            mode TEXT DEFAULT 'paper'
         )
         """
     )
 
-    # Migration: Add market and exchange_code columns if they don't exist
+    # Migration: Add columns if they don't exist (backward-compatible schema upgrades)
     cursor = conn.execute("PRAGMA table_info(trades)")
     columns = {row[1] for row in cursor.fetchall()}
 
@@ -45,6 +46,8 @@ def init_db(db_path: str) -> sqlite3.Connection:
         conn.execute("ALTER TABLE trades ADD COLUMN selection_context TEXT")
     if "decision_id" not in columns:
         conn.execute("ALTER TABLE trades ADD COLUMN decision_id TEXT")
+    if "mode" not in columns:
+        conn.execute("ALTER TABLE trades ADD COLUMN mode TEXT DEFAULT 'paper'")
 
     # Context tree tables for multi-layered memory management
     conn.execute(
@@ -167,6 +170,7 @@ def log_trade(
     exchange_code: str = "KRX",
     selection_context: dict[str, any] | None = None,
     decision_id: str | None = None,
+    mode: str = "paper",
 ) -> None:
     """Insert a trade record into the database.
 
@@ -182,6 +186,8 @@ def log_trade(
         market: Market code
         exchange_code: Exchange code
         selection_context: Scanner selection data (RSI, volume_ratio, signal, score)
+        decision_id: Unique decision identifier for audit linking
+        mode: Trading mode ('paper' or 'live') for data separation
     """
     # Serialize selection context to JSON
     context_json = json.dumps(selection_context) if selection_context else None
@@ -190,9 +196,10 @@ def log_trade(
         """
         INSERT INTO trades (
             timestamp, stock_code, action, confidence, rationale,
-            quantity, price, pnl, market, exchange_code, selection_context, decision_id
+            quantity, price, pnl, market, exchange_code, selection_context, decision_id,
+            mode
         )
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
         """,
         (
             datetime.now(UTC).isoformat(),
@@ -207,6 +214,7 @@ def log_trade(
             exchange_code,
             context_json,
             decision_id,
+            mode,
         ),
     )
     conn.commit()

src/main.py

@@ -822,6 +822,7 @@ async def trading_cycle(
         exchange_code=market.exchange_code,
         selection_context=selection_context,
         decision_id=decision_id,
+        mode=settings.MODE if settings else "paper",
     )
 
     # 7. Latency monitoring
@@ -1318,6 +1319,7 @@ async def run_daily_session(
                 market=market.code,
                 exchange_code=market.exchange_code,
                 decision_id=decision_id,
+                mode=settings.MODE,
             )
 
     logger.info("Daily trading session completed")