Summary

Adds arch property to iOS app config, allowing Detox to pass --arch to xcrun simctl launch. This lets you control which architecture slice of a universal binary runs on the simulator —
useful for testing x86_64 behavior under Rosetta on Apple Silicon machines.

Motivation

Xcode 26 introduced split simulator runtimes: Apple Silicon (arm64-only) and Universal (arm64 + x86_64 via Rosetta 2). On Universal runtimes, simctl launch --arch=x86_64 spawns the x86_64
slice. This matters for CI and testing: floating-point precision differs between architectures, and some third-party SDKs still ship x86_64-only simulator slices.

What changed

• App config: new optional arch property ('x86_64' or 'arm64') on ios.app configs
• Config validation: rejects invalid values and non-iOS app types
• Plumbing: arch flows from app config through RuntimeDevice.launchApp() → SimulatorDriver.launchApp() → AppleSimUtils.launch() → --arch=<value> on the simctl command
• Types: DetoxIosAppConfig updated in detox.d.ts
• Docs: app config documentation updated

Usage

{
  "type": "ios.app",
  "binaryPath": "ios/build/Build/Products/Debug-iphonesimulator/example.app",
  "arch": "x86_64"
}