`skillshare init --discover` finds four agents that I don't recognize

[skaurus]

I've just installed skillshare. skillshare doctor correctly recognize that I have Copilot, Cursor and Claude. However, skillshare init --discover reports this:

  Select agents to add (0/4 selected)                                                                                                                        
                                                                                                                                                             
  4 agents                                                                                                                                                   
                                                                                                                                                             
▌ [ ] witsy                                                                                                                                                  
▌ /Users/username/.agents/skills (empty)                                                                                                             
▌ [ ] zed                                                                                                                                                    
▌ /Users/username/.agents/skills (empty)                                                                                                             
▌ [ ] warp                                                                                                                                                   
▌ /Users/username/.agents/skills (empty)                                                                                                             
▌ [ ] dexto                                                                                                                                                  
▌ /Users/username/.agents/skills (empty)

I'm using Warp as my terminal, but I don't have the other three. Why does this happen?