feat: initial upbit auto-trader implementation

Strategy C: volatility breakout (Larry Williams K=0.5) AND momentum
(MA20 + 2x volume surge) must both trigger for a buy signal.

Hard rules:
- Trailing stop: sell when price drops -10% from peak
- Max budget: 1,000,000 KRW total, up to 3 positions (333,333 KRW each)
- Scan top 20 KRW tickers by 24h trading volume every 60s
- Monitor positions every 10s

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

core/market.py

@@ -0,0 +1,62 @@
+"""Market data utilities."""
+
+from __future__ import annotations
+
+import logging
+
+import pyupbit
+import requests
+
+logger = logging.getLogger(__name__)
+
+TOP_N = 20  # 거래량 상위 N개 종목만 스캔
+_TICKER_URL = "https://api.upbit.com/v1/ticker"
+
+
+def get_top_tickers() -> list[str]:
+    """24시간 거래대금 상위 KRW 마켓 티커 반환."""
+    try:
+        all_tickers = pyupbit.get_tickers(fiat="KRW")
+        if not all_tickers:
+            return []
+
+        # 100개씩 나눠서 조회 (URL 길이 제한)
+        chunk_size = 100
+        ticker_data = []
+        for i in range(0, len(all_tickers), chunk_size):
+            chunk = all_tickers[i:i + chunk_size]
+            params = {"markets": ",".join(chunk)}
+            resp = requests.get(_TICKER_URL, params=params, timeout=5)
+            resp.raise_for_status()
+            ticker_data.extend(resp.json())
+
+        # 스테이블코인 제외
+        EXCLUDE = {"KRW-USDT", "KRW-USDC", "KRW-DAI", "KRW-BUSD"}
+        ticker_data = [t for t in ticker_data if t["market"] not in EXCLUDE]
+
+        # 24h 거래대금 기준 정렬
+        ticker_data.sort(key=lambda x: x.get("acc_trade_price_24h", 0), reverse=True)
+        top = [t["market"] for t in ticker_data[:TOP_N]]
+        logger.debug(f"상위 {TOP_N}개: {top[:5]}...")
+        return top
+    except Exception as e:
+        logger.error(f"get_top_tickers 실패: {e}")
+        return []
+
+
+def get_ohlcv(ticker: str, count: int = 21):
+    """일봉 OHLCV 데이터 반환."""
+    try:
+        return pyupbit.get_ohlcv(ticker, interval="day", count=count)
+    except Exception as e:
+        logger.error(f"get_ohlcv({ticker}) 실패: {e}")
+        return None
+
+
+def get_current_price(ticker: str) -> float | None:
+    """현재가 반환."""
+    try:
+        return pyupbit.get_current_price(ticker)
+    except Exception as e:
+        logger.error(f"get_current_price({ticker}) 실패: {e}")
+        return None