live-fs-roots — remove a served filesystem root and apply it live.

Path comes from a {"path": ...} JSON body ("root" accepted too) or a ?path= query param. It is normalized then stripped from the tenant's persisted executor_config.filesystem_roots across all projects. Because add_fs_roots only ADDS, removal is pushed live with set_fs_roots (a full-list replace) so the running connector stops serving it WITHOUT a restart. Returns the updated union of roots plus live status.