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

config/nvim/init.lua

@@ -165,6 +165,7 @@ vim.pack.add({
     { src = 'https://github.com/mistweaverco/kulala.nvim' },
     { src = 'https://github.com/moyiz/blink-emoji.nvim' },
     { src = 'https://github.com/neovim/nvim-lspconfig' },
+    { src = 'https://github.com/norcalli/nvim-colorizer.lua' },
     { src = 'https://github.com/nvim-lua/plenary.nvim' }, 
     { src = 'https://github.com/nvim-lualine/lualine.nvim' },
     { src = 'https://github.com/nvim-mini/mini.ai' },