feat: 리밸런싱 엔진 V1 + GAS 버그 수정 (2026-06-13)

주요 변경:
- tools/build_rebalance_engine_v1.py: REBALANCE_ENGINE_V1 신규
  * account_snapshot 직접 합산(_build_snap_position_map) → 소수주 분리 행 병합
  * 레짐 소스 macro.REGIME_PRELIM 최우선 (GAS 와 동일)
- src/gas_adapter_parts/gdf_06_rebalance.gs: runRebalanceSheet_() 신규
  * Logger.log / getSpreadsheet_() 로 run_all 연동 수정
- src/gas_adapter_parts/gdc_01_fetch_fundamentals.gs
  * _mergePositionRecord_(): 소수주 중복 행 합산 신규
  * parseInt → parseFloat (qty, availQty)
- src/gas_adapter_parts/gdf_01_price_metrics.gs
  * 미보유 종목 SELL_READY → WATCH_EXIT_SIGNAL
- spec/41_release_dag.yaml: build_rebalance_sheet 노드 추가 (step_count 63)
- spec/51_formula_lifecycle_registry.yaml: REBALANCE_ENGINE_V1 등록

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

src/quant_engine/v7_hardening_common.py

@@ -0,0 +1,80 @@
+from __future__ import annotations
+
+import hashlib
+import json
+from pathlib import Path
+from typing import Any
+
+
+ROOT = Path(__file__).resolve().parents[2]
+TEMP = ROOT / "Temp"
+
+
+def rp(path_str: str | Path) -> Path:
+    path = Path(path_str)
+    return path if path.is_absolute() else ROOT / path
+
+
+def load_json(path: str | Path) -> dict[str, Any]:
+    p = rp(path)
+    if not p.exists():
+        return {}
+    try:
+        payload = json.loads(p.read_text(encoding="utf-8"))
+    except Exception:
+        return {}
+    return payload if isinstance(payload, dict) else {}
+
+
+def save_json(path: str | Path, payload: dict[str, Any]) -> Path:
+    p = rp(path)
+    p.parent.mkdir(parents=True, exist_ok=True)
+    p.write_text(json.dumps(payload, ensure_ascii=False, indent=2), encoding="utf-8")
+    return p
+
+
+def sha256_hex(path: str | Path) -> str:
+    p = rp(path)
+    return hashlib.sha256(p.read_bytes()).hexdigest()
+
+
+def first_non_null(*values: Any) -> Any:
+    for value in values:
+        if value is not None:
+            return value
+    return None
+
+
+def extract_hctx(payload: dict[str, Any]) -> dict[str, Any]:
+    h_apex = payload.get("hApex")
+    data_apex = ((payload.get("data") or {}).get("_harness_context")) if isinstance(payload.get("data"), dict) else None
+    if isinstance(h_apex, dict) and isinstance(data_apex, dict):
+        merged = dict(data_apex)
+        merged.update(h_apex)
+        return merged
+    if isinstance(h_apex, dict):
+        return h_apex
+    if isinstance(data_apex, dict):
+        return data_apex
+    return payload if isinstance(payload, dict) else {}
+
+
+def rows(v: Any) -> list[dict[str, Any]]:
+    if isinstance(v, list):
+        return [x for x in v if isinstance(x, dict)]
+    if isinstance(v, str) and v.strip():
+        try:
+            parsed = json.loads(v)
+            return rows(parsed)
+        except Exception:
+            return []
+    if isinstance(v, dict):
+        for key in ("rows", "data", "tickers", "items"):
+            candidate = v.get(key)
+            if isinstance(candidate, list):
+                return [x for x in candidate if isinstance(x, dict)]
+    return []
+
+
+def temp_json(name: str) -> dict[str, Any]:
+    return load_json(TEMP / name)