Replace the plain-text `nomarchy-menu theme` list with a grid of real
desktop previews. The grid, the Name→slug map and the active `✓` mark
are generated at eval time from the preset JSONs (`readDir` + `fromJSON`
in rofi.nix); "active" is just `t.slug`, since every switch rebuilds the
menu. Grouped dark-first then light in one scrollable grid (the previews
make the mode obvious — no light/dark submenu split), `flow: horizontal`
so Down scrolls row-by-row.
Previews are committed as themes/<slug>/preview.png at 480×270 (~2.4 MB
for all 21). rofi's element-icon `size` is single-value → a *square*
cell that *contains* the icon, so a 16:9 preview would letterbox; a
build-time imagemagick step centre-crops each to a square so it fills
the cell edge-to-edge (source stays 16:9, crop is reversible). The
window width is derived from `themeGridIconW` so a column is exactly the
icon side — no slack margins. Themes without a preview degrade to a
plain-name row.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Bernardo Magri
e1cf190dd2
