Group A: source upstream binaries instead of self-built artifacts

The AUR does not allow packages to ship a binary tarball built by the
maintainer - a -bin package must repackage a deliverable published by
upstream. These six packages now do that:

  snapx-bin            upstream's self-contained Linux tar.zst
  zapzap-bin           upstream's pure-Python wheel
  faugus-launcher-bin  upstream's arch-independent .deb
  wiiudownloader-bin   upstream's AppImage
  waydroid-helper-bin  upstream's AppImage
  chiaki-ng-bin        upstream's AppImage

All six drop build_artifact() and switch to refresh_checksums(), so CI no
longer builds or hosts anything - it only tracks upstream's assets.

Where the asset name carries build metadata that does not follow from
pkgver (snapx, faugus-launcher), refresh_checksums() resolves it via the
GitHub API and syncs an _asset variable in the PKGBUILD.

Dependency lists are re-derived from what the bundles actually resolve
outside themselves; the AppImage payloads land in /opt with wrappers in
/usr/bin, because their entry points resolve paths relative to argv[0].

waydroid-helper-bin/pkg.sh

@@ -1,39 +1,22 @@
-# waydroid-helper-bin - prebuilt package of https://github.com/ayasa520/waydroid-helper
-# (GTK4 + LibAdwaita GUI for Waydroid configuration/extensions, Python).
+# waydroid-helper-bin - Waydroid Helper
+# (https://github.com/ayasa520/waydroid-helper), a GTK4 + LibAdwaita GUI for
+# Waydroid configuration and extension installation.
 #
-# Upstream only ships AppImages, so build_artifact() builds the meson project
-# from the release tarball.
+# Upstream publishes an AppImage per release, which the PKGBUILD unpacks and
+# installs into /opt - so there is no build step here, only pkgver and the
+# checksum are refreshed on a new version.
 
 UPSTREAM_REPO="ayasa520/waydroid-helper"
 
-# Installed in CI (pacman) before build_artifact runs.
-BUILD_DEPS=(meson ninja python python-setuptools glib2 glib2-devel gettext)
-
 latest_version() {
   gh api "repos/$UPSTREAM_REPO/releases/latest" --jq '.tag_name' | sed 's/^v//'
 }
 
-# build_artifact <version> <output-file>
-build_artifact() {
-  local ver="$1" outfile="$2"
-  local workdir destdir srctree
-  workdir="$(mktemp -d)"
-  destdir="$(mktemp -d)"
-
-  curl -sfL "https://github.com/$UPSTREAM_REPO/archive/refs/tags/v$ver.tar.gz" | tar -xz -C "$workdir"
-  srctree="$workdir/waydroid-helper-$ver"
-
-  meson setup "$workdir/build" "$srctree" --prefix=/usr --buildtype=release
-  meson install -C "$workdir/build" --destdir "$destdir"
-
-  # These caches are generated by pacman hooks; shipping them would cause
-  # file conflicts on install.
-  rm -f "$destdir/usr/share/glib-2.0/schemas/gschemas.compiled" \
-        "$destdir/usr/share/applications/mimeinfo.cache" \
-        "$destdir/usr/share/icons/hicolor/icon-theme.cache"
-
-  tar --zstd --sort=name --owner=0 --group=0 --numeric-owner --mtime='@0' \
-      -cf "$outfile" -C "$destdir" usr
-
-  rm -rf "$workdir" "$destdir"
+# refresh_checksums <version> <pkgbuild-path>
+refresh_checksums() {
+  local ver="$1" pkgbuild="$2"
+  local sha
+  sha="$(curl -sfL "https://github.com/$UPSTREAM_REPO/releases/download/v$ver/waydroid-helper-$ver-x86_64.AppImage" \
+    | sha256sum | cut -d' ' -f1)"
+  sed -i "s|^sha256sums=.*|sha256sums=('$sha')|" "$pkgbuild"
 }