KytyPlus v4.6

Games can now be launched straight out of a .zar archive, and a class of shader-descriptor
aborts no longer kills the game.

ZArchive (`.zar`) loading, without extraction

Load Game gained a "ZArchive game image (.zar)..." option. The archive is read in place:
members are decompressed on demand through the emulator's archive!/member path namespace, so
nothing is extracted, staged or copied to disk. The archive reader, the file layer and the guest
/app0 mount already supported this — what was missing was --game routing and a launcher
entry point.
.zar files inside a configured game folder now appear in the list like .ffpfsc and
.exfat images do, and Explorer's "Open with" and --open-image accept them.
The mount-progress dialog no longer waits on an archive. That dialog is driven by markers
printed by the external NAPS helper, which an in-process archive never emits; sharing one
predicate between the two would have left it spinning forever on a .zar. Formats that need the
helper are now tested separately from formats that merely launch.
A .zar with no eboot.bin says so instead of failing later as an unclear missing-file
error.

An unmapped shader buffer descriptor is now treated as unbound. A descriptor whose base
address is not committed at all went through a clamp that reports a fatal error and aborts.
Titles can legitimately hold a descriptor pointing into freed memory and never bind it to a
shader stage; that now degrades to the same empty binding an explicitly-zero address already
produced, with a capped log line. This is what killed Demon's Souls (PPSA01341, issues #16 and
#17) before its intro cutscene — on Windows and on Fedora alike.

The .zar path was verified against archives built for the purpose, not against a real game
.zar; none was available to test with. The mechanism is exercised end-to-end, a shipped title
in that container is not.
The Demon's Souls fix has not been run against a dump locally — it rests on the reports in #16
and #17.
Astro Bot reaches in game but is still not playable: frame rate is far from real-time on an
iGPU, and the title can still exit on its own during a session.