Add Flatpak packaging for Patchwork 5.4.0

Bundle Poncho Wonky (Patchwork 5.4.0) for x86_64 and aarch64 on the
24.08 freedesktop runtime with the Electron BaseApp. Launcher forces
Wayland when a socket is present so the app starts from terminals
outside the desktop session. Pinned versions and checksums live in
versions.sh and are validated by check-versions.sh.

patchwork.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+set -e
+
+# Electron defaults to the X11 platform even on Wayland-only sessions, which
+# fails when no X server or $DISPLAY is available. Use Wayland whenever a
+# socket is present; otherwise fall back to Electron's default (X11).
+if [ -S "${XDG_RUNTIME_DIR}/wayland-0" ]; then
+  exec zypak-wrapper /app/Patchwork/ponchowonky --ozone-platform=wayland "$@"
+fi
+
+exec zypak-wrapper /app/Patchwork/ponchowonky "$@"