fix: add missing clone manifest to bustub sg_only Dockerfile

The bustub-hyperloglog-impl-001 MCP run failed with RewardFileNotFoundError
because the sg_only Dockerfile was missing the clone manifest needed for
verifier repo restoration. Added the manifest pointing to sg-evals/bustub--d5f79431.

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

Author: sjarmak

benchmarks/ccb_feature/bustub-hyperloglog-impl-001/environment/Dockerfile.sg_only

@@ -26,6 +26,9 @@ RUN mkdir -p /logs/agent /logs/verifier
 # Mark sg_only mode so verifiers can skip local-path checks
 RUN touch /tmp/.sg_only_mode
 
+# Clone manifest for verifier repo restoration
+RUN echo '{"workdir":"/workspace","repos":[{"mirror":"sg-evals/bustub--d5f79431","target_dir":"."}]}' > /tmp/.sg_only_clone_manifest.json
+
 # Pre-create claude user and set ownership at build time.
 RUN (adduser --disabled-password --gecos '' claude 2>/dev/null || true) && \
     for d in /workspace /app /testbed /logs; do [ -d "$d" ] && chown -R claude:claude "$d"; done || true