feat: Enhance trading system with new e_min_chg_pct parameter and related logic

Changes:
- Introduced the `e_min_chg_pct` parameter to define the minimum price change percentage compared to the previous day's close, enhancing the momentum trading strategy.
- Updated various functions and classes to incorporate this new parameter, ensuring it is utilized in both backtesting and live trading scenarios.
- Improved documentation and comments to clarify the purpose and usage of the new parameter across the codebase.

Impact:
- This addition allows for more precise control over trading conditions, potentially increasing the effectiveness of the momentum strategy while maintaining system integrity and performance.

scripts/run_strategy_backtest_cli.py

@@ -170,16 +170,28 @@ def main() -> int:
     hb = threading.Thread(target=_heartbeat, args=(prog_file, stop_hb), daemon=True)
     hb.start()
     _write_progress(prog_file, pct=30, phase="engine", message="웹엔진 실행중")
+    data = None
+    http_status = 200
     try:
         with bw.app.test_request_context(f"{path}?{qs}"):
             resp = fn()
         if isinstance(resp, tuple):
+            # Flask: (jsonify(...), 500) — 본문만 취하면 실패를 성공으로 오인함
+            http_status = int(resp[1]) if len(resp) > 1 else 200
             resp = resp[0]
+        elif hasattr(resp, "status_code"):
+            try:
+                http_status = int(resp.status_code)
+            except (TypeError, ValueError):
+                http_status = 200
         data = resp.get_json(silent=True) if hasattr(resp, "get_json") else None
         if not isinstance(data, dict):
             raise RuntimeError(f"응답 JSON 아님: {type(resp)}")
-        if data.get("error") and not data.get("summary") and not data.get("ok", True):
-            raise RuntimeError(str(data.get("error")))
+        # 핸들러가 jsonify({"error": ...}, 500) 을 주면 summary 없이 error 만 옴
+        if http_status >= 400 or (
+            data.get("error") and not data.get("summary")
+        ):
+            raise RuntimeError(str(data.get("error") or f"HTTP {http_status}"))
     finally:
         stop_hb.set()
         try:
@@ -187,10 +199,14 @@ def main() -> int:
         except Exception:
             pass
 
+    if not isinstance(data, dict):
+        raise RuntimeError("백테 응답 없음")
+
     elapsed = time.time() - t0
     summary = data.get("summary") or {}
     trades = data.get("trades") or []
     out = dict(data)
+    out.pop("error", None)
     out["ok"] = True
     out["job_id"] = job_id
     out["kind"] = "strategy_bt_cli"