fix(ci): create Temp directory if missing in secrets validation

When validate_gitea_secrets_contract_v1.py runs in CI environment,
Temp directory may not exist. Add directory creation before writing
output JSON.

This fixes: FileNotFoundError in Validate Security Configuration job

Phase 0 Week 1: CI Baseline (Attempt 4)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

tools/validate_gitea_secrets_contract_v1.py

@@ -62,6 +62,7 @@ def main() -> int:
         "errors": errors,
     }
     out = ROOT / "Temp" / "gitea_secrets_contract_v1.json"
+    out.parent.mkdir(parents=True, exist_ok=True)
     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