Replace swaylock with gtklock; centralise theme palette

- Replace swaylock with gtklock (username + password form lockscreen)
- Add gtklock/config.ini and gtklock/style.css (Tomorrow Night theme)
- Update niri keybindings and swayidle to invoke gtklock -d
- Update packages.txt: swaylock -> gtklock
- Update install.sh: add AUR helper detection (yay/paru), symlink gtklock configs
- Add theme/colors.css (CSS custom properties) and theme/colors.json
- Update waybar/style.css, wofi/style.css, gtklock/style.css to import shared palette
- Update README.md with project summary and component table
- Add ARCHITECTURE.md and CLAUDE.md

install.sh

@@ -2,11 +2,21 @@
 
 set -e
 
-echo "==> Installing packages"
-sudo pacman -S --needed - < packages.txt
+echo "==> Detecting AUR helper"
+if command -v yay &>/dev/null; then
+  AUR_HELPER=yay
+elif command -v paru &>/dev/null; then
+  AUR_HELPER=paru
+else
+  echo "ERROR: No AUR helper found. Install yay or paru first." >&2
+  exit 1
+fi
+
+echo "==> Installing packages (using $AUR_HELPER)"
+$AUR_HELPER -S --needed - < packages.txt
 
 echo "==> Creating config directories"
-mkdir -p ~/.config/{niri,waybar,wofi,mako,alacritty,gtk-3.0,gtk-4.0,swaylock,fish} ~/.config/environment.d ~/.config/xdg-desktop-portal
+mkdir -p ~/.config/{niri,waybar,wofi,mako,alacritty,gtk-3.0,gtk-4.0,gtklock,fish} ~/.config/environment.d ~/.config/xdg-desktop-portal
 
 echo "==> Linking configs"
 
@@ -18,7 +28,8 @@ ln -sf "$(pwd)/waybar/style.css" ~/.config/waybar/style.css
 ln -sf "$(pwd)/wofi/config" ~/.config/wofi/config
 ln -sf "$(pwd)/wofi/style.css" ~/.config/wofi/style.css
 ln -sf "$(pwd)/mako/config" ~/.config/mako/config
-ln -sf "$(pwd)/swaylock/config" ~/.config/swaylock/config
+ln -sf "$(pwd)/gtklock/config.ini" ~/.config/gtklock/config
+ln -sf "$(pwd)/gtklock/style.css" ~/.config/gtklock/style.css
 ln -sf "$(pwd)/fish/config.fish" ~/.config/fish/config.fish
 ln -sf "$(pwd)/starship/starship.toml" ~/.config/starship.toml
 ln -sf "$(pwd)/alacritty/alacritty.toml" ~/.config/alacritty/alacritty.toml