[ScottMorris]

Summary

• Audio plugins: the Arch AppImage workflow now installs gst-plugins-base, gst-plugins-good and gst-plugin-pipewire by default. WebKitGTK plays audio through GStreamer, and webkit2gtk-4.1 only depends on the GStreamer libraries, so quick-sharun had no plugins to deploy and packaged apps logged GStreamer element autoaudiosink not found.
• Deploy: DEPLOY_GSTREAMER=1 is set for the assemble step so the plugins are always copied into the AppDir.
• Guard: the build fails if libgstautodetect.so (which provides autoaudiosink) is missing from the AppDir after quick-sharun runs.
• Consumers: folio, emoji-nook, jar and lieutenant-fizz call this workflow at @main without overriding extra-pacman-packages, so all four pick up the change. A consumer that passes its own extra-pacman-packages replaces the default and needs to include the three packages.

Test plan

• Ran the workflow's setup, dependency and assemble steps locally in the pinned Arch container against the lieutenant-fizz 0.3.0 .deb: the guard passed and quick-sharun --test went OK
• libgstautodetect.so, libgstpipewire.so and libgstalsa.so are present in AppDir/lib/gstreamer-1.0/
• Launched the resulting AppImage on a desktop Linux host: no autoaudiosink message and no GLib-GObject-CRITICAL lines; only the harmless canberra-gtk-module notice remains
• Game audio plays from the locally built AppImage
• Run a consumer release against this branch in CI
• Check the AppImage size increase is acceptable (107 MB locally)