signal-desktop: resources/app.asar inspection

gen.sh - the script used to generate this
PKGBUILD - the PKGBUILD used to build and rebuild the arch package

makepkg index      - signal-desktop-1.39.6-1-x86_64.pkg.tar.zst
makerepropkg index - signal-desktop-1.39.6-1-x86_64.pkg.tar.zst
upstream index     - signal-desktop_1.39.6_amd64.deb

diff makepkg-vs-makerepropkg - this needs to be empty for the package to be reproducible
diff makepkg-vs-upstream - for fun, this isn't super relevant because the build environment is very different