Hairpin elements should be swappable via palettes

Your idea

When a dynamic is selected, clicking a different dynamic in palettes will swap it in for the old dynamic. Hairpin elements should work the same way.

If any of these four element types are selected in the score, clicking another one in palettes should replace it:

• Hairpin: Crescendo line
• Hairpin: Decrescendo line
• Hairpin: Crescendo hairpin
• Hairpin: Decrescendo hairpin

Current behavior

https://github.com/user-attachments/assets/f1c6d47b-ea32-49b3-a42f-526b250318be

Problem to be solved

Examples:

• I want to replace a crescendo hairpin with a crescendo line
• I want to replace a crescendo hairpin with a decrescendo hairpin

Prior art

No response

Additional context

No response

Checklist

• This request follows the guidelines for reporting issues
• I have verified that this feature request has not been logged before, by searching the issue tracker for similar requests

Start by tracing how palette selections replace selected dynamics and how the four hairpin element types are represented in the score. Done means selecting any listed hairpin and clicking another listed hairpin in the palette replaces the original with the chosen type, including line-to-hairpin and crescendo-to-decrescendo swaps.