feat: add omarchy theme template system with management scripts

- New default/themed/ templates (alacritty, btop, foot, ghostty, helix,
  hyprland, hyprlock, kitty, mako, obsidian, rofi, swayosd, tmux,
  walker, waybar, keyboard.rgb, gum.env, etc.)
- Add omarchy-* theme management scripts (install, refresh, set, remove,
  update, bg-set, colors-from-alacritty, current, etc.)
- Add omarchy restart/hook scripts (btop, hyprctl, hypridle, mako, tmux)
- Add installer/environment.sh for shared env vars
- Add 19 theme directories with colors.toml, vscode.json, backgrounds,
  and app-specific configs (catppuccin, everforest, gruvbox, nord,
  tokyo-night, rose-pine, etc.)
- Update bing-wallpaper script to use new .config/omarchy path

themes/kanagawa/colors.toml

@@ -0,0 +1,23 @@
+accent = "#7e9cd8"
+cursor = "#c8c093"
+foreground = "#dcd7ba"
+background = "#1f1f28"
+selection_foreground = "#c8c093"
+selection_background = "#2d4f67"
+
+color0 = "#090618"
+color1 = "#c34043"
+color2 = "#76946a"
+color3 = "#c0a36e"
+color4 = "#7e9cd8"
+color5 = "#957fb8"
+color6 = "#6a9589"
+color7 = "#c8c093"
+color8 = "#727169"
+color9 = "#e82424"
+color10 = "#98bb6c"
+color11 = "#e6c384"
+color12 = "#7fb4ca"
+color13 = "#938aa9"
+color14 = "#7aa89f"
+color15 = "#dcd7ba"

themes/kanagawa/vscode.json

@@ -0,0 +1,4 @@
+{
+  "name": "Kanagawa",
+  "extension": "qufiwefefwoyn.kanagawa"
+}