Native iPhone port of Factorio 2.0.77

Run the original macOS ARM64 game code on iOS:
- tools/retarget.py: header-only Mach-O retargeting to an iOS dylib
- platform/native: UIKit host and macOS API shims (AppKit for SDL's
  Cocoa backend, CoreGraphics displays, CoreAudio device, Metal device
  properties, Wuffs PNG decoding, Steam and peripheral stubs)
- touch, overlay, iOS keyboard and hardware keyboard input
- tools/build_native.py: build, sign, install, data copy, launch
- docs: build guide, controls, architecture

Also includes the earlier static-translation research (ARM64 -> WASM ->
native) under docs/research, runtime/, tests/ and tools/.

No game files are included; the build reads them from a local install.

runtime/deserialiser_host.h

@@ -0,0 +1,10 @@
+#ifndef FACTORIO_DESERIALISER_HOST_H
+#define FACTORIO_DESERIALISER_HOST_H
+#include "factorio_deser.h"
+#include "guest_heap.h"
+struct w2c_deser__host {
+  w2c_factorio__deser *module;
+  FactorioGuestHeap heap;
+  unsigned reads, zero_calls, unsupported_calls, version_errors;
+};
+#endif