Record public input source binding

[yoshifuminakamura]

Summary

• record public input source URL, ref, resolved commit, and recipe in benchmark input metadata
• classify public input source commit coverage as Covered input evidence
• keep reuse readiness aligned with public input source commit evidence

Tests

• .venv/bin/python -m pytest result_server/tests/test_results_loader.py result_server/tests/test_evidence_snapshot.py result_server/tests/test_usage_route.py result_server/tests/test_portal_list_templates.py
• .venv/bin/python result_server/tests/run_result_server_tests.py
• bash scripts/tests/test_bk_input_info.sh
• bash scripts/tests/test_result_common_json_contract.sh
• bash scripts/tests/test_estimation_common_json_contract.sh
• bash syntax and shellcheck checks for changed shell files