fix: synology py38 compatibility and KIS validation deps

src/quant_engine/kis_api_client_v1.py

@@ -26,8 +26,6 @@ import sys
 from pathlib import Path
 from typing import Any
 
-import requests
-
 ROOT = Path(__file__).resolve().parents[2]
 if str(ROOT) not in sys.path:
     sys.path.insert(0, str(ROOT))
@@ -36,6 +34,14 @@ REAL_DOMAIN = "https://openapi.koreainvestment.com:9443"
 MOCK_DOMAIN = "https://openapivts.koreainvestment.com:29443"
 TOKEN_CACHE_DIR = ROOT / "Temp"
 
+
+def _requests():
+    try:
+        import requests  # type: ignore
+    except Exception as exc:  # pragma: no cover - surfaced as runtime validation error
+        raise RuntimeError(f"import_error: {exc}") from exc
+    return requests
+
 # ── [CRITICAL] 주문 차단 목록 — 절대 수정/완화 금지 (governance/rules/06_no_direct_api_trading.yaml) ──
 # "/trading/" 하위 경로는 주문(order)뿐 아니라 계좌잔고조회(inquire-balance)도 포함한다.
 # 계좌 보유종목/잔고는 governance/rules/07_no_kis_account_balance_query.yaml에 의해
@@ -126,6 +132,7 @@ def _issue_or_reuse_token(creds: KisCredentials) -> str:
         except (json.JSONDecodeError, KeyError, ValueError):
             pass
 
+    requests = _requests()
     resp = requests.post(
         f"{creds.domain}/oauth2/tokenP",
         json={"grant_type": "client_credentials", "appkey": creds.app_key, "appsecret": creds.app_secret},
@@ -155,6 +162,7 @@ def _send_request(creds: KisCredentials, path: str, tr_id: str, params: dict[str
         "tr_id": tr_id,
         "custtype": "P",
     }
+    requests = _requests()
     resp = requests.get(f"{creds.domain}{path}", headers=headers, params=params, timeout=15)
     resp.raise_for_status()
     return resp.json()