* fix(desktop): keep attachment close and code copy icons visible
Hover-only opacity-0 hid the composer remove control and code-block copy button, so they stayed clickable but invisible on Windows and other no-hover surfaces.
* test(desktop): pin attachment close and code copy visibility at rest
The remove chip and code-block copy control must stay in the tree without a hover class, so Windows and no-hover surfaces cannot hide them again.
b519ce29ad