feat: US market code 정합성, Telegram 명령 4종, 손절 모니터링 (#132)

- MARKET_SHORTHAND + expand_market_codes()로 config "US" → schedule "US_NASDAQ/NYSE/AMEX" 자동 확장
- /report, /scenarios, /review, /dashboard 텔레그램 명령 추가
- price_change_pct를 trading_cycle과 run_daily_session에 주입
- HOLD시 get_open_position 기반 손절 모니터링 및 자동 SELL 오버라이드
- 대시보드 /api/status 동적 market 조회로 변경

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

tests/test_market_schedule.py

@@ -7,6 +7,7 @@ import pytest
 
 from src.markets.schedule import (
     MARKETS,
+    expand_market_codes,
     get_next_market_open,
     get_open_markets,
     is_market_open,
@@ -199,3 +200,28 @@ class TestGetNextMarketOpen:
             enabled_markets=["INVALID", "KR"], now=test_time
         )
         assert market.code == "KR"
+
+
+class TestExpandMarketCodes:
+    """Test shorthand market expansion."""
+
+    def test_expand_us_shorthand(self) -> None:
+        assert expand_market_codes(["US"]) == ["US_NASDAQ", "US_NYSE", "US_AMEX"]
+
+    def test_expand_cn_shorthand(self) -> None:
+        assert expand_market_codes(["CN"]) == ["CN_SHA", "CN_SZA"]
+
+    def test_expand_vn_shorthand(self) -> None:
+        assert expand_market_codes(["VN"]) == ["VN_HAN", "VN_HCM"]
+
+    def test_expand_mixed_codes(self) -> None:
+        assert expand_market_codes(["KR", "US", "JP"]) == [
+            "KR",
+            "US_NASDAQ",
+            "US_NYSE",
+            "US_AMEX",
+            "JP",
+        ]
+
+    def test_expand_preserves_unknown_code(self) -> None:
+        assert expand_market_codes(["KR", "UNKNOWN"]) == ["KR", "UNKNOWN"]