Packages: Add cmux and ghostty

- cmux: cask, macOS-only (Ghostty-based terminal for AI coding agents).
- ghostty: GUI on both platforms — cask on macOS, and dnf via the
  scottames/ghostty COPR on Fedora (no clean apt package exists for
  Debian/Ubuntu).

Author: jdevera

home/.chezmoidata/package_specs.yml

@@ -289,3 +289,12 @@ softwarePackages:
     cask: utm
   monitorcontrol:
     cask: monitorcontrol
+  cmux:
+    homepage: https://www.cmux.dev
+    cask: cmux
+  ghostty:
+    homepage: https://ghostty.org
+    cask: ghostty
+    dnf:
+      package: ghostty
+      copr: scottames/ghostty

home/.chezmoidata/packages.yml

@@ -121,3 +121,7 @@ packages:
     only_when: [macos]
   - name: monitorcontrol
     only_when: [macos]
+  - name: cmux
+    only_when: [macos]
+  - name: ghostty
+    only_when: [gui]