fix: import sys in M0 artifact resolver

Co-Authored-By: Codex <noreply@openai.com>

Author: Pigbibi

.github/workflows/publish-m0-research-ledger.yml

@@ -111,6 +111,7 @@ jobs:
           python3 - "${artifacts_metadata}" <<'PY'
           import json
           import os
+          import sys
           from pathlib import Path
 
           payload = json.loads(Path(sys.argv[1]).read_text(encoding="utf-8"))

python/tests/test_manual_m0_research_publisher_workflow.py

@@ -38,6 +38,7 @@ def test_workflow_is_manual_and_binds_one_explicit_successful_qar_artifact(self)
         self.assertIn('metadata.get("head_branch") != "main"', workflow)
         self.assertIn('metadata.get("event") not in {"schedule", "workflow_dispatch"}', workflow)
         self.assertIn("QAR artifact workflow-run binding mismatch", workflow)
+        self.assertIn('import sys\n          from pathlib import Path', workflow)
         self.assertIn("QAR artifact must contain exactly one dated M0 source snapshot", workflow)
         self.assertIn("m0_research_source_snapshot_[0-9]{4}-[0-9]{2}-[0-9]{2}", workflow)
         self.assertIn("M0_SOURCE_SNAPSHOT_SHA256", workflow)