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

script/omarchy-theme-set-obsidian

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# omarchy:summary=Sync Omarchy theme to all Obsidian vaults
+# omarchy:hidden=true
+
+CURRENT_THEME_DIR="$HOME/.config/omarchy/current/theme"
+
+[[ -f $CURRENT_THEME_DIR/obsidian.css ]] || exit 0
+
+jq -r '.vaults | values[].path' ~/.config/obsidian/obsidian.json 2>/dev/null | while read -r vault_path; do
+  [[ -d $vault_path/.obsidian ]] || continue
+
+  theme_dir="$vault_path/.obsidian/themes/Omarchy"
+  mkdir -p "$theme_dir"
+
+  [[ -f $theme_dir/manifest.json ]] || cat >"$theme_dir/manifest.json" <<'EOF'
+{
+  "name": "Omarchy",
+  "version": "1.0.0",
+  "minAppVersion": "0.16.0",
+  "description": "Automatically syncs with your current Omarchy system theme colors and fonts",
+  "author": "Omarchy",
+  "authorUrl": "https://omarchy.org"
+}
+EOF
+
+  cp "$CURRENT_THEME_DIR/obsidian.css" "$theme_dir/theme.css"
+done