Google Drive link for `serper_search_cache.jsonl` is still a placeholder

[Hadeslm]

Hi, thanks for open-sourcing Syn-Plan-Research.

I noticed that the README section for downloading the optional web search cache still contains a placeholder Google Drive link:

Download serper_search_cache.jsonl from Google Drive: link
Because the link uses YOUR_FILE_ID, users cannot download the provided serper_search_cache.jsonl cache. This makes evaluation/RL setup harder, since running without the cache may require additional Serper API usage and cost.

Could you please update the README with the correct Google Drive link, or clarify whether the cache is currently unavailable?

Thanks!