Fix empty username

[codefiles]

Fixes #3532

[correctmost]

It looks like _check_for_correct_username is supposed to ensure that the username starts with a lowercase letter or underscore (but it's not doing so).

[codefiles]

I can trigger the message The username you entered is invalid to appear below the input field by starting a username without a lowercase letter or underscore. I am not sure why it is not working for you.

Seems like skip would be the intended outcome when pressing enter at an empty input field.

[codefiles]

Did you mean, why is an empty string not triggering the validator? The validator will not be used when text is an empty string.

archinstall/archinstall/tui/curses_menu.py

Lines 562 to 563 in b2b36a2

	if text and self._validator:
	if (err := self._validator(text)) is not None:

[correctmost]

Ah, yes, that was the confusing part. I assumed the validator function would run on all inputs :).

[codefiles]

An empty string is essentially no input, so there is nothing to validate. Makes sense to me anyway.