MusicXML export Part does not include dynamic attached to grace note

Issue type

Import/export issue

Description with steps to reproduce

1. Create a score with grace notes and a dynamic on the grace notes
2. Export part as MusicXML
3. Open the MusicXML, see that the dynamic is missing

Dynamic appears in main score MusicXML export

Supporting files, videos and screenshots

Score

MusicXML Part

MusicXML Score

In which versions of MuseScore Studio is this issue present?

OS: macOS Tahoe (26.2), Arch.: arm64, MuseScore Studio version (64-bit): 5.0.0-260505040, revision: github-musescore-musescore-36b2e93

Regression

No.

Operating system

MacOS Tahoe 26.2

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

No source file or test is named. Start by reproducing the grace-note and dynamic case, then compare Part and main-score MusicXML exports; done when the Part export includes the dynamic and a regression test covers it.