refactor: migrate to template-based theme system, clean up old per-theme configs

- Remove per-theme app configs (alacritty, foot, ghostty, hyprland,
  hyprlock, mako, rofi, swayosd, tmux, walker, waybar, etc.) now
  handled by default/themed/ templates
- Update omarchy scripts (bg-next, list, set) for new template flow
- Update configs: bootstrap, nvim, rofi, tmux, mako
- Tweak installers (02-install-base.sh, btop, desktop, goose, nvim,
  obsidian, theme, tmux)
- Remove obsolete hyprland-rofi-* and hyprland-walker-* scripts
- Update neovim.lua across remaining themes

installer/02-install-base.sh

@@ -6,7 +6,7 @@ fi
 
 paru -Sy --needed iptables-nft
 
-$DOTFILE_DIR/package-installer $DOTFILE_DIR/packages/sjb-base.packages
+$DOTFILES_DIR/package-installer $DOTFILES_DIR/packages/sjb-base.packages
 
 if [[ -x "$(command -v systemctl)" ]]; then
 	sudo systemctl enable --now bluetooth.service