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/retro-82/colors.toml

@@ -0,0 +1,35 @@
+# Accent and UI colors
+accent = "#faa968"
+active_border_color = "#faa968"
+active_tab_background = "#faa968"
+
+# Cursor colors
+cursor = "#f6dcac"
+
+# Primary colors
+foreground = "#f6dcac"
+background = "#05182e"
+
+# Selection colors
+selection_foreground = "#00172e"
+selection_background = "#faa968"
+
+# Normal colors (ANSI 0-7)
+color0 = "#303442"
+color1 = "#f85525"
+color2 = "#028391"
+color3 = "#e97b3c"
+color4 = "#faa968"
+color5 = "#3f8f8a"
+color6 = "#8cbfb8"
+color7 = "#a7c9c6"
+
+# Bright colors (ANSI 8-15)
+color8 = "#134e5a"
+color9 = "#f85525"
+color10 = "#028391"
+color11 = "#e97b3c"
+color12 = "#faa968"
+color13 = "#3f8f8a"
+color14 = "#8cbfb8"
+color15 = "#f6dcac"