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].

zapzap-bin/pkg.sh

@@ -1,65 +1,28 @@
-# zapzap-bin - prebuilt package of https://github.com/rafatosta/zapzap
-# (WhatsApp desktop client written in PyQt6 + PyQt6-WebEngine).
+# zapzap-bin - ZapZap (https://github.com/rafatosta/zapzap), WhatsApp desktop
+# client written in PyQt6 + PyQt6-WebEngine.
 #
-# Upstream ships deb/AppImage bundles that vendor all of Qt; instead we build
-# the (pure-Python) wheel and install it against the system PyQt6 packages,
-# like the AUR source package does.
+# Upstream publishes a pure-Python wheel per release, which the PKGBUILD
+# installs against the system PyQt6 packages - unlike upstream's deb/AppImage
+# bundles, which vendor all of Qt. Icon, desktop file and metainfo are not
+# part of the wheel and come from the matching source tag.
+#
+# Upstream tags carry no "v" prefix.
 
 UPSTREAM_REPO="rafatosta/zapzap"
 
-# Installed in CI (pacman) before build_artifact runs.
-BUILD_DEPS=(python python-build python-installer python-setuptools python-wheel)
-
 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="$2"
-  local workdir destdir srctree staging sitedir entry
-  workdir="$(mktemp -d)"
-  destdir="$(mktemp -d)"
-  staging="$(mktemp -d)"
+# refresh_checksums <version> <pkgbuild-path>
+refresh_checksums() {
+  local ver="$1" pkgbuild="$2"
+  local sha_whl sha_src
 
-  curl -sfL "https://github.com/$UPSTREAM_REPO/archive/refs/tags/$ver.tar.gz" | tar -xz -C "$workdir"
-  srctree="$workdir/zapzap-$ver"
+  sha_whl="$(curl -sfL "https://github.com/$UPSTREAM_REPO/releases/download/$ver/zapzap-$ver-py3-none-any.whl" \
+    | sha256sum | cut -d' ' -f1)"
+  sha_src="$(curl -sfL "https://github.com/$UPSTREAM_REPO/archive/refs/tags/$ver.tar.gz" \
+    | sha256sum | cut -d' ' -f1)"
 
-  (cd "$srctree" && python -m build --wheel --no-isolation)
-  python -m installer --destdir="$staging" "$srctree"/dist/*.whl
-
-  # The wheel installs into site-packages, whose path changes with every
-  # Python minor bump and would silently break a prebuilt package. Relocate
-  # to a fixed dir and use our own launcher instead of the generated console
-  # script (entry point parsed from pyproject.toml).
-  sitedir="$(find "$staging/usr/lib" -maxdepth 2 -type d -name site-packages)"
-  [[ -d "$sitedir/zapzap" ]] || { echo "zapzap module not found in $sitedir" >&2; return 1; }
-  mkdir -p "$destdir/usr/lib/zapzap"
-  mv "$sitedir/zapzap" "$sitedir"/zapzap-*.dist-info "$destdir/usr/lib/zapzap/"
-
-  entry="$(python -c "import tomllib; print(tomllib.load(open('$srctree/pyproject.toml','rb'))['project']['scripts']['zapzap'])")"
-  mkdir -p "$destdir/usr/bin"
-  cat > "$destdir/usr/bin/zapzap" << EOF
-#!/usr/bin/python3
-import sys
-
-sys.path.insert(0, "/usr/lib/zapzap")
-from ${entry%%:*} import ${entry#*:}
-
-sys.exit(${entry#*:}())
-EOF
-  chmod 755 "$destdir/usr/bin/zapzap"
-
-  # Icon, desktop file and metainfo are not part of the wheel.
-  install -Dm644 "$srctree/share/icons/com.rtosta.zapzap.svg" \
-    "$destdir/usr/share/icons/hicolor/scalable/apps/com.rtosta.zapzap.svg"
-  install -Dm644 "$srctree/share/applications/com.rtosta.zapzap.desktop" \
-    "$destdir/usr/share/applications/com.rtosta.zapzap.desktop"
-  install -Dm644 "$srctree/share/metainfo/com.rtosta.zapzap.appdata.xml" \
-    "$destdir/usr/share/metainfo/com.rtosta.zapzap.appdata.xml"
-
-  tar --zstd --sort=name --owner=0 --group=0 --numeric-owner --mtime='@0' \
-      -cf "$outfile" -C "$destdir" usr
-
-  rm -rf "$workdir" "$destdir" "$staging"
+  sed -i "s|^sha256sums=.*|sha256sums=('$sha_whl' '$sha_src')|" "$pkgbuild"
 }