Appending ?subtree=true to file/dir URLs breaks when the URL already has query params

Appending ?subtree=true to file/dir URLs breaks when the URL already has query params: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). We construct links to files and directories in a few places (the file-match results list, RepoFileLink , and the "go to dir"/"go…