I have already checked through the existing feature requests and found no duplicates

• Yes

Is this a server-specific feature?

Navidrome

What do you want to be added?

Not sure if this would be server specific to Navidrome or available on Subsonic.

Relating to Smart Playlist queries.

When creating or Editing Smart Playlist queries, I would like to be able to toggle between the current builder editor and a raw JSON editor. This would ease importing playlist found online or copying templates.

For example, I recently added a secondary library to my server. I only want my smart playlists to apply to the primary library and now I need to add that as a rule to all of my playlists. This would be much easier to accomplish by copy/pasting some raw JSON.