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.

tools/check_target_device.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+"""Validate downloaded build-4 reports and audit the signed iOS executable."""
+import hashlib
+import json
+import subprocess
+from datetime import datetime
+from pathlib import Path
+ROOT=Path(__file__).resolve().parents[1]
+OUT=ROOT/'build/target-deserialiser'
+reports={name:json.loads((OUT/('iphone-'+name+'-result.json')).read_text())
+         for name in ('target','layout','map-header','version')}
+target=reports['target']
+assert all(r['app_build']=='4' and r['app_version']=='0.1.0' for r in reports.values())
+assert len({r['run_id'] for r in reports.values()})==1
+assert len({r['build_id'] for r in reports.values()})==1
+times=[datetime.fromisoformat(r['recorded_at'].replace('Z','+00:00')) for r in reports.values()]
+assert (max(times)-min(times)).total_seconds()<30
+assert target['status']=='pass' and target['code']==0
+assert target['allocations']==4 and target['pool_capacity']==64 and target['initialized_targets']==64
+assert target['heap_bytes']==2104
+assert reports['version']['status']=='pass'
+assert reports['map-header']['status']=='pass'
+assert reports['map-header']['modern_64_bit'] and reports['map-header']['legacy_32_bit_sentinel']
+layout=reports['layout']
+desktop=json.loads((ROOT/'build/save-layout/desktop-real-save.json').read_text())
+assert layout['status']==0 and layout['input_sha256']==desktop['input_sha256']
+for key in ('header_offset','next_offset','mod_count','tick_fields_hex'):
+    assert layout[key]==desktop['decoded_layout'][key]
+binary=ROOT/'build/ios-device/Build/Products/Release-iphoneos/FactorioPort.app/FactorioPort'
+assert target['build_id'].encode() in binary.read_bytes()
+dependencies=subprocess.check_output(['xcrun','otool','-L',str(binary)],text=True)
+imports=subprocess.check_output(['xcrun','nm','-u',str(binary)],text=True)
+symbols=subprocess.check_output(['xcrun','nm',str(binary)],text=True)
+assert 'steam' not in (dependencies+imports).lower()
+for symbol in ('_factorio_rng_original','_factorio_version_original','_factorio_map_header_original',
+               '_factorio_target_original','_native_target_allocate'):
+    assert symbol not in symbols
+report={'status':'pass','app_build':'4','run_id':target['run_id'],'build_id':target['build_id'],
+        'device':'iPhone 15 Pro','target_constructor':target,
+        'same_launch_version_map_header_and_actual_save':'pass',
+        'input_sha256':layout['input_sha256'],'steam_dependency_or_import':False,
+        'desktop_oracle_symbols':False,'signed_binary_sha256':hashlib.sha256(binary.read_bytes()).hexdigest(),
+        'scope':'original initialization graph and existing header probes; no loaded world or gameplay'}
+(OUT/'device-verification.json').write_text(json.dumps(report,indent=2)+'\n')
+print('PASS: build 4 same-launch device reports, actual-save regression, signed binary dependency/oracle audit')