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/vantablack/colors.toml

@@ -0,0 +1,31 @@
+# UI Colors (extended)
+accent = "#8d8d8d"
+cursor = "#ffffff"
+
+# Primary colors
+foreground = "#ffffff"
+background = "#000000"
+
+# Selection colors
+selection_foreground = "#000000"
+selection_background = "#ffffff"
+
+# Normal colors (ANSI 0-7)
+color0 = "#404040"
+color1 = "#a4a4a4"
+color2 = "#b6b6b6"
+color3 = "#cecece"
+color4 = "#8d8d8d"
+color5 = "#9b9b9b"
+color6 = "#b0b0b0"
+color7 = "#ececec"
+
+# Bright colors (ANSI 8-15)
+color8 = "#5c5c5c"
+color9 = "#a4a4a4"
+color10 = "#b6b6b6"
+color11 = "#cecece"
+color12 = "#8d8d8d"
+color13 = "#9b9b9b"
+color14 = "#b0b0b0"
+color15 = "#ffffff"