Install Emacs via the omarchy-emacs AUR package

Point the Emacs entry in the install-editor menu at a dedicated
omarchy-install-editor-emacs script, matching the pattern already used
for Helix, VSCode, and Zed. The script installs the omarchy-emacs AUR
package and runs its installer, which pulls in emacs-wayland, applies
the theme/font integration, and enables the user emacs.service.

This is the AUR-packaged approach dhh suggested on #4807 (superseding
the in-tree integration proposed there), now that the package exists and
is maintained on the AUR. End-user behavior is unchanged except that a
freshly installed Emacs now tracks the active Omarchy theme and font out
of the box.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

bin/omarchy-install-editor-emacs

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# omarchy:summary=Install Emacs with Omarchy theme and font integration via the omarchy-emacs AUR package
+
+echo "Installing Emacs..."
+omarchy-pkg-aur-add omarchy-emacs && omarchy-install-emacs