Instrument names: "Hide if there is only 1 instrument" style not respected in continuous view

[fidwell]

Issue type

Engraving bug (incorrect score rendering)

Description with steps to reproduce

1. Create a score with one staff.
2. Go to "Style" -> "Score" -> "Instrument names" -> "Hide if there is only 1 instrument".
3. Observe that instrument name is properly hidden in page view.
4. Switch to continuous view (horizontal).
5. Observe that instrument name appears again.

Supporting files, videos and screenshots

In which versions of MuseScore Studio is this issue present?

MuseScore Studio version (64-bit): 4.7.0-253380330, revision: github-musescore-musescore-62cdcc9

Regression

No. (I do not know if this issue was present in MuseScore 3, but I have never seen it working correctly in MuseScore 4.)

Operating system

Windows 11 Version 25H2 or later, Arch.: x86_64

Additional context

No response

Checklist

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