[pfista]

Adds a native Apple Silicon macOS target for the existing 32-bit game ABI. The build reuses Android's guest compiler pipeline, runtime and host services, plus Linux's file helpers; the macOS executable runs ARM64 instructions while game pointers and data layouts remain 32-bit.

The app keeps SDL/ANGLE Metal rendering, keyboard/mouse and controller input, audio, networking, native first-launch Xbox game-data selection/import, saved data selection, and an ad-hoc signed drag-to-Applications DMG. Game assets remain external. No app icon is included in the PR or packaged app; macOS supplies its generic application icon.

Review by commit

Commit	Scope
ca1bde14	Shared guest/host reuse, desktop platform hooks and renderer compatibility
abc5faba	Mac memory/OS adapters, minimal native app, importer and packaging
e45041cd	Mac build/package CI and installation instructions

Total: 3,621 additions / 80 deletions across 58 files: 3,484 implementation lines, 53 CI lines, and 84 documentation lines. The game retains its existing data structures and the Windows/Linux architectures stay the same.

Automatic updates/Sparkle, signed/notarized release automation, expanded native settings, profiling, experimental geometry caching and iOS-specific paths are deferred. The native app menu provides About, Choose Game Data on Next Launch, Open Saves Folder and Quit; display and controls use the game's settings.

Validation

• Full local Mac guest/host/app build, strict signature verification, and startup from the read-only DMG passed.
• Additional runtime probes passed on the same implementation at 1dcb7edc: guest ABI/rebasing/libc, memory/syscalls, UDP, SDL audio, rendering, native import/persistence/rollback, and packaging. Those test sources are outside this PR's scope; current CI retains build and package verification.
• The compiler pass produced identical IR to the earlier Mac path for four game/runtime modules; errno translation matched the earlier implementation in the tested cases.
• Local LAN and encrypted-invite matches passed with two instances, two players and bidirectional gameplay updates. A remote internet invite also joined successfully during user playtesting. Broader NAT configurations and physical controllers need further playtesting.
• Fresh Linux/Windows/Android CI and macOS build/package CI pass at e45041cd.

Build, install and verification instructions. One standard macos-26 job builds, audits the bundle, verifies the DMG checksum, ARM64 architecture and strict signatures, and uploads halo-macos-arm64-dmg; no signing credentials are required. The separate community-map PR #63 is independent of this contribution.

[cybersecurity]

macOS support cannot be officially added due to the github runners for them costing 10x as much as Linux runners (I also don't own any apple products so I cannot do testing). Long term, I will likely link one of the MacOS / IOS forks in the main repo for people to find.