fix: br clipboard rotation transform being ignored

[MrJoshuaT]

Overview

Brush clipboard rotation transform was ignored

Fixes #3265

Description

Applies the rotation transform when combining with the original transform.

Worth noting when testing, the main branch bukkit adapter for 1.21.6 uses 1.21.8-R0.1-20250720.221224-10 paperDevBundle and I had to update to 1.21.8-R0.1-20250825.020248-46 to build it for testing, as the original is unavailable

Submitter Checklist

• Make sure you are opening from a topic branch (/feature/fix/docs/ branch (right side)) and not your main branch.
• Ensure that the pull request title represents the desired changelog entry.
• New public fields and methods are annotated with @since TODO.
• I read and followed the contribution guidelines.

[PierreSchwang]

looks reasonable