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.

docs/controls.md

@@ -0,0 +1,62 @@
+# Controls
+
+Factorio is played with a mouse and keyboard. The port turns touches into mouse events and
+offers three ways to press keys. The game receives ordinary macOS key events with Mac key codes,
+so Factorio's own key bindings and settings apply unchanged.
+
+## Touch
+
+| Gesture | Sent to the game | Typical use |
+| --- | --- | --- |
+| Tap | Left click (double tap = double click) | Buttons, placing, opening entities |
+| Drag with one finger | Left button held while moving | Placing rows of items, dragging in GUIs |
+| Long press (0.6 s) and keep holding | Right button held; moving drags with it | Mining resources, trees and rocks; removing buildings |
+| Two-finger drag | Mouse wheel | Zooming the map view, scrolling lists |
+
+Touch positions map 1:1 to the game's pixels, so taps land exactly under the finger.
+
+## On-screen overlay
+
+| Button | Key |
+| --- | --- |
+| Left stick | W A S D (walking); diagonals press two keys |
+| E | Inventory |
+| Q | Pipette / clear cursor |
+| R | Rotate |
+| F | Pick up items |
+| M | Map |
+| T | Technologies |
+| ⇧ | Shift, sticky |
+| Ctrl | Control, sticky |
+| Esc (top left) | Escape: menu, close windows |
+| Tab (top left) | Tab |
+| ◐ (top right) | Hide or show the stick and the key buttons |
+| ⌨︎ (top right) | Open or close the iOS keyboard |
+
+The key labels match Factorio's default bindings. If you rebind keys in the game, the buttons
+still send the same physical keys.
+
+**Sticky modifiers.** Tap ⇧ or Ctrl and the button turns orange. The modifier stays pressed for
+your next click, long press or typed key, then releases. Tap it again to release it without
+using it. Example: Ctrl, then tap an assembler to transfer all items.
+
+## iOS keyboard and extra keys
+
+The ⌨︎ button opens the standard iOS keyboard for chat, save names and search fields. Every
+character you type is also a key press, so letters work as hotkeys while the keyboard is open.
+
+Above the keyboard is a scrollable bar with the keys iOS keyboards lack: Esc, Tab, Ctrl, Alt
+and ⇧ (sticky), arrow keys, Enter, Del, \`, Home, End, Page Up, Page Down and F1–F12.
+
+Typing uses the US key layout; accented characters are sent as text only.
+
+## Hardware keyboard
+
+A Bluetooth or USB-C keyboard is passed through key by key, including modifiers, function keys
+and key releases, so held keys and combinations behave as on a Mac. iOS reserves some
+Command-key shortcuts for itself.
+
+## Interface size
+
+At native resolution Factorio's interface is small on a phone. Set **Settings → Interface → UI
+scale** in the game to about 175–200 %. This does not lower the rendering resolution.