fix(ai_trade): V1_TOKEN_PATH default를 legacy/signal_v1/ 경유로 수정 (F1)

코드 리뷰 F1: V1이 legacy/signal_v1/로 이동되었으나 config.py default가
구 경로를 가리켜 .env 미설정 시 KIS REST가 V1 token file missing으로 실패.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ai_trade/config.py

@@ -31,7 +31,7 @@ class Settings:
     v1_token_path: Path = field(
         default_factory=lambda: Path(
             os.getenv("V1_TOKEN_PATH",
-                      str(Path(__file__).parent.parent / "signal_v1" / "data" / "kis_token.json"))
+                      str(Path(__file__).parent.parent / "legacy" / "signal_v1" / "data" / "kis_token.json"))
         )
     )
     chronos_model: str = field(default_factory=lambda: os.getenv("CHRONOS_MODEL", "amazon/chronos-2"))

ai_trade/tests/test_config_token_path.py

@@ -0,0 +1,22 @@
+"""F1 — V1_TOKEN_PATH default가 legacy/signal_v1/ 경유인지 검증."""
+from pathlib import Path
+
+from ai_trade.config import Settings
+
+
+def test_v1_token_default_path_uses_legacy_dir(monkeypatch):
+    """env에 V1_TOKEN_PATH 없으면 legacy/signal_v1/data/kis_token.json"""
+    monkeypatch.delenv("V1_TOKEN_PATH", raising=False)
+    settings = Settings()
+    expected_suffix = Path("legacy") / "signal_v1" / "data" / "kis_token.json"
+    assert str(settings.v1_token_path).endswith(str(expected_suffix)), (
+        f"expected default to end with {expected_suffix}, got {settings.v1_token_path}"
+    )
+
+
+def test_v1_token_env_override_wins(monkeypatch, tmp_path):
+    """env로 명시한 경로가 default를 덮어씀."""
+    custom = tmp_path / "custom_token.json"
+    monkeypatch.setenv("V1_TOKEN_PATH", str(custom))
+    settings = Settings()
+    assert settings.v1_token_path == custom