Shortcuts should still work while focus is in dynamics popup

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

Split from #26249

1. Add/select a dynamic
2. Press tab to move keyboard focus to the popup

After focusing in the popup, some shortcuts work (i.e. voice assignment) but others do nothing. These shortcuts should be possible without having to press esc first:

• Alt + Left/Right arrows to select previous/next element (popup should close)
• Alt + Up/Down arrows to select other elements at that beat position (popup should close)
• Shift + Left/Right arrows to move the dynamic by beat position (popup should remain open)
• Ctrl + C to copy (popup should remain open)
• Ctrl + X to cut (popup should close)

Supporting files, videos and screenshots

https://github.com/user-attachments/assets/02922086-5b5b-42d1-8b8e-3c64ee7867f3

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

Nightly

Regression

No.

Operating system

macOS 15

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

Reproduce the dynamic popup workflow by selecting a dynamic, pressing Tab, and trying each listed shortcut on macOS. Trace the popup’s keyboard handling and selection actions from that interaction. Done means all listed shortcuts work while focus is in the popup, with the specified close or remain-open behavior.