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>

tools/validate_decision_graph.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+
+import argparse
+from pathlib import Path
+
+import yaml
+
+
+EXPECTED = [
+    "data_quality",
+    "portfolio_health",
+    "cash",
+    "heat",
+    "stop_tp",
+    "anti_chase",
+    "regime",
+    "sector_beta",
+    "style",
+    "sizing",
+    "execution",
+]
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--graph", required=True)
+    parser.add_argument("--strict", action="store_true")
+    args = parser.parse_args()
+    graph = yaml.safe_load(Path(args.graph).read_text(encoding="utf-8"))
+    nodes = [n["id"] for n in graph.get("nodes", [])]
+    errors: list[str] = []
+    if nodes != EXPECTED:
+        errors.append("node order mismatch")
+    if len(graph.get("edges", [])) != len(EXPECTED) - 1:
+        errors.append("edge count mismatch")
+    if errors:
+        print("FAIL")
+        for e in errors:
+            print(e)
+        return 1
+    print("DECISION_GRAPH_OK")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
+