Theme listing page with family grouping (litmus-gyq0)


Status	Done · `archived`
Type	Feature
Priority	normal
Parent	(litmus-m8ze)

Theme listing page organized by theme family.

Summary of Changes

Added family grouping to theme listing page:

family.rs: theme_family() extracts family from name using known prefix list; group_by_family() groups themes
Listing page now shows themes organized under family headings (Catppuccin, Gruvbox, etc.)
Standalone themes (Dracula, Nord, Kanagawa) appear as their own single-theme groups