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.

platform/native/shim/coregraphics.c

@@ -0,0 +1,76 @@
+// macOS-only CoreGraphics display APIs, re-exported alongside iOS CoreGraphics.
+// One display (FX_DISPLAY_ID) with the phone's landscape size; mode changes are refused.
+#include <CoreFoundation/CoreFoundation.h>
+#include <string.h>
+#include "fx.h"
+
+typedef uint32_t CGDirectDisplayID;
+typedef int32_t CGError;
+typedef CFDataRef CGDisplayModeRef;  // CFType so CFRetain/CFEqual/CFArray callbacks work
+typedef struct { size_t w, h, pw, ph; double hz; } fx_mode;
+
+static fx_mode fx_current_mode(void) {
+    CGSize s = fx_screen_points();
+    double k = fx_screen_scale();
+    return (fx_mode){(size_t)s.width, (size_t)s.height, (size_t)(s.width * k), (size_t)(s.height * k), 60.0};
+}
+static const fx_mode *fx_m(CGDisplayModeRef m) { return (const fx_mode *)CFDataGetBytePtr(m); }
+
+FX_EXPORT const CFStringRef kCGDisplayShowDuplicateLowResolutionModes = CFSTR("kCGDisplayShowDuplicateLowResolutionModes");
+
+FX_EXPORT CGError CGGetOnlineDisplayList(uint32_t max, CGDirectDisplayID *displays, uint32_t *count) {
+    if (displays && max) displays[0] = FX_DISPLAY_ID;
+    if (count) *count = 1;
+    return 0;
+}
+FX_EXPORT CGDirectDisplayID CGMainDisplayID(void) { return FX_DISPLAY_ID; }
+FX_EXPORT int CGDisplayIsMain(CGDirectDisplayID d) { return d == FX_DISPLAY_ID; }
+FX_EXPORT CGDirectDisplayID CGDisplayMirrorsDisplay(CGDirectDisplayID d) { return 0; }
+FX_EXPORT CGRect CGDisplayBounds(CGDirectDisplayID d) { CGSize s = fx_screen_points(); return CGRectMake(0, 0, s.width, s.height); }
+FX_EXPORT size_t CGDisplayPixelsWide(CGDirectDisplayID d) { return (size_t)fx_screen_points().width; }
+FX_EXPORT size_t CGDisplayPixelsHigh(CGDirectDisplayID d) { return (size_t)fx_screen_points().height; }
+FX_EXPORT CGSize CGDisplayScreenSize(CGDirectDisplayID d) {
+    // Physical size in millimetres at ~460 ppi (iPhone 15 Pro class display).
+    double k = fx_render_divisor(); CGSize s = fx_screen_points();
+    return CGSizeMake(s.width * k / 460.0 * 25.4, s.height * k / 460.0 * 25.4);
+}
+FX_EXPORT CGDisplayModeRef CGDisplayCopyDisplayMode(CGDirectDisplayID d) {
+    fx_mode m = fx_current_mode();
+    return CFDataCreate(NULL, (const UInt8 *)&m, sizeof m);
+}
+FX_EXPORT CFArrayRef CGDisplayCopyAllDisplayModes(CGDirectDisplayID d, CFDictionaryRef options) {
+    CGDisplayModeRef m = CGDisplayCopyDisplayMode(d);
+    CFArrayRef a = CFArrayCreate(NULL, (const void **)&m, 1, &kCFTypeArrayCallBacks);
+    CFRelease(m);
+    return a;
+}
+FX_EXPORT void CGDisplayModeRelease(CGDisplayModeRef m) { if (m) CFRelease(m); }
+FX_EXPORT size_t CGDisplayModeGetWidth(CGDisplayModeRef m) { return fx_m(m)->w; }
+FX_EXPORT size_t CGDisplayModeGetHeight(CGDisplayModeRef m) { return fx_m(m)->h; }
+FX_EXPORT size_t CGDisplayModeGetPixelWidth(CGDisplayModeRef m) { return fx_m(m)->pw; }
+FX_EXPORT size_t CGDisplayModeGetPixelHeight(CGDisplayModeRef m) { return fx_m(m)->ph; }
+FX_EXPORT double CGDisplayModeGetRefreshRate(CGDisplayModeRef m) { return fx_m(m)->hz; }
+FX_EXPORT uint32_t CGDisplayModeGetIOFlags(CGDisplayModeRef m) { return 0x7; }  // valid | safe | default
+FX_EXPORT int CGDisplayModeIsUsableForDesktopGUI(CGDisplayModeRef m) { return 1; }
+FX_EXPORT CFStringRef CGDisplayModeCopyPixelEncoding(CGDisplayModeRef m) {
+    return CFStringCreateCopy(NULL, CFSTR("--------RRRRRRRRGGGGGGGGBBBBBBBB"));
+}
+FX_EXPORT CGError CGDisplaySetDisplayMode(CGDirectDisplayID d, CGDisplayModeRef m, CFDictionaryRef o) { return 1000; }
+FX_EXPORT CGError CGDisplayCapture(CGDirectDisplayID d) { return 0; }
+FX_EXPORT CGError CGCaptureAllDisplays(void) { return 0; }
+FX_EXPORT CGError CGDisplayRelease(CGDirectDisplayID d) { return 0; }
+FX_EXPORT CGError CGReleaseAllDisplays(void) { return 0; }
+FX_EXPORT int32_t CGShieldingWindowLevel(void) { return 2147483630; }
+FX_EXPORT CGError CGAcquireDisplayFadeReservation(float seconds, uint32_t *token) { if (token) *token = 1; return 0; }
+FX_EXPORT CGError CGReleaseDisplayFadeReservation(uint32_t token) { return 0; }
+FX_EXPORT CGError CGDisplayFade(uint32_t token, float d, float a, float b, float r, float g, float bl, int sync) { return 0; }
+FX_EXPORT uint32_t CGDisplayIDToOpenGLDisplayMask(CGDirectDisplayID d) { return 1; }
+FX_EXPORT uint32_t CGDisplayIOServicePort(CGDirectDisplayID d) { return 0; }
+FX_EXPORT CGError CGAssociateMouseAndMouseCursorPosition(int connected) { return 0; }
+FX_EXPORT CGError CGWarpMouseCursorPosition(CGPoint p) { return 0; }
+FX_EXPORT CGError CGDisplayMoveCursorToPoint(CGDirectDisplayID d, CGPoint p) { return 0; }
+FX_EXPORT CGError CGGetDisplayTransferByTable(CGDirectDisplayID d, uint32_t cap, float *r, float *g, float *b, uint32_t *count) {
+    if (count) *count = 0;
+    return 1000;
+}
+FX_EXPORT CGError CGSetDisplayTransferByTable(CGDirectDisplayID d, uint32_t n, const float *r, const float *g, const float *b) { return 1000; }