Fix dark theme, animation speed, kitty opacity; add README

- libadwaita apps (nautilus, gnome-text-editor) rendered light because
  gsettings-desktop-schemas + dconf were missing, so the color-scheme
  prefer-dark autostart silently no-op'd. Add both packages.
- Replace Hyprland's slow default animations with the reference laptop's
  bezier curves + per-leaf speeds (hl.curve + hl.animation).
- kitty background_opacity 0.88 -> 0.6 to match the laptop; drop the
  macOS-only background_blur line (Hyprland supplies the blur).
- Add README.md documenting the actual image, build, and test flow.

iso/airootfs/etc/skel/.config/kitty/kitty.conf

@@ -1,8 +1,9 @@
 # BOS kitty config.
 # Translucent background so Hyprland's blur shows through behind the terminal,
 # while text stays fully opaque. Colours are left to kitty's default / pywal.
-background_opacity 0.88
-background_blur 1
+# 0.6 matches the reference laptop; the actual blur is supplied by Hyprland's
+# decoration:blur (kitty's own background_blur is macOS-only).
+background_opacity 0.6
 
 font_family      JetBrains Mono
 font_size        11.0