Custom key signatures don't apply microtonal accidentals

[Linus3141601]

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

1. Create a custom key signature that includes a microtonal accidental (e.g. f half-sharp)
2. Apply that key signature and place a note where the accidental was placed (e.g. f)
3. It plays back f while the custom key signature includes a half-sharp at the f.

Supporting files, videos and screenshots

https://github.com/user-attachments/assets/85cf0856-b9e4-4ff3-aa53-3b84da3754a8

What is the latest version of MuseScore Studio where this issue is present?

OS: Windows 11 Version 2009 or later, Arch.: x86_64, MuseScore Studio version (64-bit): 4.4.4-243260401, revision: github-musescore-musescore-c5c81eb

Regression

I was unable to check

Operating system

Windows 11 (possibly more OS's. am unable to check)

Additional context

No response

Checklist

• [x] This report follows the guidelines for reporting bugs and issues
• [X] I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• [X] I have attached all requested files and information to this report
• [X] I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

[sammik]

I think, core issue is same as in others, f. ex. #20162

In fact, there are couple of different problems of same core - missing microtonal "states" (and none of them is described. It is not issue MU plays f atural, because it is f natural)

1. problem is missing natural before f
2. problem is, MU "thinks", accidental in key signature is natural (it has "natural" state)
3. problem is, similar as before, notes are added as natural, even if they should be microsharp (or whatever)