[BUG] +a face attribute in css filetype does not allow for custom cursor

### Version of Kakoune Kakoune 2026.04.12 ### Reproducer Set cursor to ```kak hook global InsertIdle .* %{ set-face global PrimaryCursor "default,default+u" set-face global PrimaryCursorEol "rgb:%opt{red},default+u" set-face global SecondaryCursor "default,default+u" set-face global SecondaryCursorEol "rgb:%opt{cyan},default+u" } hook global NormalIdle .* %{ set-face global PrimaryCursor "default,default+r" set-face global PrimaryCursorEol "rgb:%opt{red},default+r" set-face global SecondaryCursor "default,default+r" set-face global SecondaryCursorEol "rgb:%opt{cyan},default+r" } ``` Open a css file and try to sroll over css properties or digit ### Outcome The cursor disappears ### Expectations The cursor should be the reveresed color of the face ### Additional information https://github.com/user-attachments/assets/cce39871-b70f-46ce-96bc-a579db00e9a6