Sakura Line: retheme the whole desktop from the wallpaper

Palette sampled from bspwm/wallpaper/wallpaper.jpg and applied per-role
(not per-hex, so terminal green stays green and nvim's LineNr/Comment
stay recessive) across st, kitty, polybar, rofi, dunst, nvim, qt5ct/qt6ct
and GTK 2/3/4.

Also:
- rofi drun centred, icons enabled
- polybar translucent (true ARGB) and rounded; picom corner-radius, with
  the desktop layer and fullscreen windows excluded
- fix qt5ct color_scheme_path pointing at a nonexistent /home/carrie
- export QT_QPA_PLATFORMTHEME so qt6ct is actually consulted
- point GTK at an icon theme that exists on this system
- add .config/rice: one-shot install.sh (--dry-run supported), package
  list, vendored st config.h (gitignored upstream) and the particles
  wallpaper-layer source, so a clone reproduces the rice

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Cn3dHfbgNYdbZvzb1b3GQt

.config/qt6ct/colors/dc.conf

@@ -2,6 +2,6 @@
 # Format: FG, BTN_BG, bright, less_br, dark, less_dark, txt_fg, br_text, btn_fg, txt_bg, bg, shadow, sel_bg, sel_fg, link, visited, alt_bg, default, tooltip_bg, tooltip_fg, placeholder_fg, accent
 
 [ColorScheme]
-active_colors=#feffd3, #262626, #303030, #262626, #5a5d61, #444649, #feffd3, #feffd3, #feffd3, #1a1a1a, #141414, #000000, #e1c47d, #141414, #e1c47d, #c2a86c, #1a1a1a, #feffd3, #262626, #feffd3, #778284, #e1c47d
-disabled_colors=#778284, #262626, #303030, #262626, #5a5d61, #444649, #778284, #778284, #778284, #1a1a1a, #141414, #000000, #5a5d61, #141414, #778284, #778284, #1a1a1a, #778284, #262626, #778284, #778284, #5a5d61
-inactive_colors=#feffd3, #262626, #303030, #262626, #5a5d61, #444649, #feffd3, #feffd3, #feffd3, #1a1a1a, #141414, #000000, #c2a86c, #141414, #c2a86c, #c2a86c, #1a1a1a, #feffd3, #262626, #feffd3, #778284, #c2a86c
+active_colors=#e9eefb, #201b30, #2e2842, #201b30, #5b5478, #3d3752, #e9eefb, #e9eefb, #e9eefb, #191527, #0f0d17, #000000, #92b9ea, #0f0d17, #92b9ea, #7c9ede, #191527, #e9eefb, #201b30, #e9eefb, #7f7796, #92b9ea
+disabled_colors=#7f7796, #201b30, #2e2842, #201b30, #5b5478, #3d3752, #7f7796, #7f7796, #7f7796, #191527, #0f0d17, #000000, #5b5478, #0f0d17, #7f7796, #7f7796, #191527, #7f7796, #201b30, #7f7796, #7f7796, #5b5478
+inactive_colors=#e9eefb, #201b30, #2e2842, #201b30, #5b5478, #3d3752, #e9eefb, #e9eefb, #e9eefb, #191527, #0f0d17, #000000, #7c9ede, #0f0d17, #7c9ede, #7c9ede, #191527, #e9eefb, #201b30, #e9eefb, #7f7796, #7c9ede

.config/qt6ct/qt6ct.conf

@@ -1,7 +1,7 @@
 [Appearance]
 color_scheme_path=~/.config/qt6ct/colors/dc.conf
 custom_palette=true
-icon_theme=Gruvbox-Plus-Dark
+icon_theme=Adwaita
 standard_dialogs=default
 style=Fusion