android: run PS4 and PS5 titles on device

[Force67]

PS4 and PS5 titles now run on the phone through the NativeActivity app, at the
same point the host is at.

The load-bearing fix is that the Android build had no shader recompiler at all.
delta/gpu enables the direct SPIR-V backend only when pkg_check_modules
finds SPIRV-Tools and SPIRV-Headers, and neither resolves against the NDK
sysroot, so DELTA_HAVE_SPIRV_BACKEND was quietly undefined and Recompile
was compiled out. Every PS5 draw was dropped ([agc] recompile FAILED ... draw dropped) and the frame was black. Building SPIRV-Tools with the NDK and
pointing PKG_CONFIG_LIBDIR at it turns the backend on; the CMake change here
is needed because delta_gpu is a static library, so only the library list
propagates to the final link and pkg-config yields bare -l names when cross
compiling. Two smaller build breaks came with it: memfd_create is only
declared by bionic at API 30 while we target 29, and both Android gfx backends
were missing setTitle/overlaySetPerf.

Presentation was a stretch to fill the surface, which made 16:9 content about
20% too wide on a 21:9 panel. Fitting it is not as simple as it looks: the
swapchain image is portrait while the window is landscape and the compositor
scales each axis independently instead of rotating, so the aspect fit is solved
in landscape screen space and the rect mapped back into image space for the
blit. Touch input and the overlay go through that same rect.

The touch controls were four hard-edged discs alpha-blended at a flat 0.40,
chosen around what Isaac needed. They are now signed distance fields resolved
with a pixel of coverage, laid out in height units so the pad keeps its
proportions on any panel, and cover twin sticks, a d-pad, the four face
buttons, shoulders, touchpad and options.

PS5 titles could not boot on Android at all: an adb-started Activity inherits
no environment, so DELTA_PS5_MODULES (and every other DELTA_* knob) was
unreachable. android_main reads <dataDir>/env.cfg before anything else and
defaults the PS5 module path to the staged firmware. The launcher only browsed
for .pkg, so it now accepts .ffpkg and extracted game folders as well.
DELTA_ANDROID_LOGFILE tees the log to a file, which is what made the
remaining failures diagnosable: logd drops bursts from a chatty uid and
anything still in the pipe is lost when the process dies, which is exactly when
a crash dump is written.

Verified on a OnePlus 15 (SM8850, Android 16): PS4 Isaac in gameplay at ~265
fps, PS4 Undertale at 30 fps and interactive to the name-entry screen, PS5
Isaac Repentance in gameplay at 210-350 fps, all with zero unsupported opcodes
and driven entirely through the on-screen pad. Both Android configurations
(DELTA_ANDROID_APP on and off) build, and each commit builds on its own. The
host build is unaffected: it still resolves SPIRV-Tools to absolute paths and
keeps the backend enabled.

Dead Cells still does not get past sceSysmoduleLoadModule for libc, but it
stops at the same place on the host, so it is not an Android regression. The
difference in symptom is that the SDK assert is stepped over by the
int 0x41/0x44/0x45 handler in crash.cpp, which is #if defined(__x86_64__)
and has no FEX equivalent, so the guest ud2 is fatal on ARM rather than
merely hanging.