feat: postgres history-first 계약과 적재 경로 추가

- PostgreSQL history contract와 schema/validator를 추가했습니다.
- .NET history store, snapshot reader, repository, migration을 연결했습니다.
- history-first 운영 모델 문서와 daily signal tracking 문구를 정리했습니다.

tools/validate_postgresql_history_contract_v1.py

@@ -0,0 +1,44 @@
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import yaml
+
+ROOT = Path(__file__).resolve().parents[1]
+CONTRACT = ROOT / "spec" / "postgresql_history_contract.yaml"
+OUT = ROOT / "Temp" / "postgresql_history_contract_v1.json"
+
+
+def main() -> int:
+    errors: list[str] = []
+    if not CONTRACT.exists():
+        errors.append("contract_missing")
+    else:
+        try:
+            data = yaml.safe_load(CONTRACT.read_text(encoding="utf-8"))
+        except Exception as exc:
+            errors.append(f"yaml_parse_error:{exc}")
+            data = {}
+        if not isinstance(data, dict):
+            errors.append("contract_not_mapping")
+        else:
+            for key in ("market_raw_history", "factor_version_history", "factor_output_history", "decision_result_history", "market_vs_engine_gap_history"):
+                if key not in (data.get("domains") or {}):
+                    errors.append(f"missing_domain:{key}")
+            if "PostgreSQL" not in json.dumps(data, ensure_ascii=False):
+                errors.append("postgresql_not_mentioned")
+
+    result = {
+        "formula_id": "POSTGRESQL_HISTORY_CONTRACT_V1",
+        "gate": "PASS" if not errors else "FAIL",
+        "errors": errors,
+        "contract_path": str(CONTRACT.relative_to(ROOT)),
+    }
+    OUT.write_text(json.dumps(result, ensure_ascii=False, indent=2), encoding="utf-8")
+    print(json.dumps(result, ensure_ascii=False, indent=2))
+    return 0 if not errors else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())