Issues with ordering of system markings in Layout panel

[avvvvve]

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

@mike-spa A few issues I found in the Layout panel, highest to lowest priority

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After opening all parts, the first system marking row in the Layout panel moves to the second position.

Screen.Recording.2025-02-18.at.1.23.55.PM.mov

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When repositioning a system object row, sometimes it disappears/causes other system markings to disappear.

Screen.Recording.2025-02-18.at.1.34.31.PM.mov

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Undo does not always update the layout panel (also some more weirdness with the point above illustrated here)

Screen.Recording.2025-02-18.at.1.36.46.PM.mov

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Also, it was by design that the first system marking row cannot be selected or moved in the Layout list. However, I found a way to select it: Click and hold on it, and while continue holding the click, mouse over another row, then mouse back over the system marking row and release the mouse. It gets selected, and you can use the arrows to reposition it.

Screen.Recording.2025-02-18.at.1.38.39.PM.mov

There's no visual cue that it can't be moved but it looks exactly like the other rows, which makes it feel a bit broken.

cc @bkunda @oktophonie

Supporting files, videos and screenshots

See above

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

#26572

Regression

No.

Operating system

macOS 15

Additional context

No response

Checklist

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• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible