I can delete rules from the library, but after restarting Zed, they reappear.

Summary

Zed: v0.210.0 (Zed Nightly 197d24437809a7d5bbd214f79e11b850367e35e2) 
OS: macOS 26.0
Memory: 64 GiB
Architecture: aarch64

Update:

Wanted to add more information here that I didn't include after fixing on my end. I believe this was a migration issue from an older format of our rules files to a newer one. I was able to "fix" the issue by copying out the rule files content, creating new rules, and deleting the old ones. I think the old ones used a json format (I can't quite recall).

I dont know which version, but I suspect if you simply download a very old Zed build, maybe from over a year ago, and made a rule, it would be in this older format, then open it in a current version of Zed and I think you'll be able to reproduce it.