fix(desktop): catalog AppImages start from the desktop menu through the shipped runtime
RPCS3 from the desktop menu exited at once: its own AppImage runtime runs
dwarfsextract from a memfd, which PRoot cannot execute (EACCES), and it has no
fallback. Emulator rail launches already avoid this by starting arm64 images
through the shipped uruntime (#1191); the menu entries the catalog writes did not.
The rule now lives in one launcher, droiddeck-appimage-exec, used by the session
and by the catalog's menu entries. Entries written by older versions are moved
to it with the existing menu migration.
RPCS3's AppImage could not start: its own runtime unpacks the image with
a dwarfsextract it runs from a memfd, which Android refuses (EACCES), and
it has no other way to run it. Emulator AppImages for arm64 now start
through the shipped uruntime, which falls back to a file in /tmp.
RPCS3 then stopped with "Null object" in utils::shm (errno 13): it reads
/proc/sys/vm/overcommit_memory to pick memfd for guest memory, and apps
cannot read it. The guest now gets the kernel's default policy (0) there
when the real file is unreadable, like file-max.
MaxsTechReview