Make open button configurable

[dain]

The list of actions in the open button should be configurable. There are a million custom IDE like looks (including custom corporate tools), so listing or knowing all of them is infeasable. Also, sometimes I have tools installed, I don't want in the list. This is one of the more frustrating things with codex app.

I suggest adding a way to customize this list in the settings. On Mac you should pickup the icon from the application by default.

[lapinvert]

Yes please. I want Sublime Text in there.

[juliusmarminge]

#7109 adds an implementation and screenshots for configurable applications in the Open menu, including discovery on the connected environment. Keeping that prior work linked here as the two proposals are consolidated.