feat(rofi): real icons, zebra rows, content-fit menus across all themes

Reworked the menu look, palette-driven so it lands on every theme:

  - Real Papirus icons in place of Nerd Font glyphs: a row() helper emits
    rofi's per-row icon protocol, and the five static menus (root, Tools,
    System, Power, Capture) map each entry to a freedesktop icon name
    (verified present in Papirus). Entry text is now clean ("Apps"), the
    case-matching is unchanged.
  - Larger icons via a new t.ui.iconSize knob (36px, generated theme); the
    summer whole-swaps keep their 40px identity.
  - Rounded, roomy rows with subtle zebra striping: alternate rows lift to
    @surface (a faint bg0 wash on the summer cream/slate windows), the
    selected row to @accent — using rofi's normal/alternate/selected row
    parities.
  - Content-fit windows: fixed-num-lines=false so a 6-entry menu stops
    reserving 8 rows of empty space (the launcher still fills + scrolls).
    Dropped the fixed height:50% from the summer .rasi so they size to
    content too — which also unhid their clipped Power/Keybindings rows.
  - Title-cased the menu prompts.

Verified by building the HM config and rendering the generated theme plus
both summer whole-swaps headlessly (sway + grim): icons resolve, zebra
shows, every menu hugs its rows.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

modules/home/theme.nix

@@ -38,6 +38,7 @@ let
       gapsOut = 12;
       borderSize = 2;
       rounding = 10;
+      iconSize = 36; # rofi launcher + menu icon size (px) for the generated theme
       activeOpacity = 1.0;
       inactiveOpacity = 0.95;
       terminalOpacity = 0.96;