I've used Alfred[1] for many years on macOS, and more recently the PowerToys Command Palette[2] on Windows.

Both are easily extensible, so you could certainly wire either up to the local (or hosted) LLM of your choice.

Side note: I just noticed the extension example in the Command Palette demo reel searches HN.

[1] https://www.alfredapp.com/

[2] https://learn.microsoft.com/en-us/windows/powertoys/command-...