Package dataset runtime resources

[Danielxu0208]

Summary

• include dataset JSONL resources in source and wheel package metadata
• resolve MedBench and LEval resources relative to their installed modules instead of the process working directory
• add arbitrary-CWD regression coverage for all three packaged resources

Why

The existing manifest omitted *.jsonl, so the MedBench entity list and two LEval battle baselines were absent from built distributions. The runtime readers also used repository-root-relative paths, causing FileNotFoundError when OpenCompass was launched outside a source checkout root.

Validation

• simulated wheel and sdist payloads include all three JSONL files
• loaded 1,685 MedBench entity choices from an unrelated working directory
• loaded both 96-sample LEval battle resources from an unrelated working directory
• Python 3.8 grammar check and relevant pre-commit hooks passed
• git diff --check