@spec android_toolchain_available?(String.t()) :: boolean()

Returns true when the Android build toolchain looks usable from the given project directory. Three signals must all be present:

1. adb is on PATH (build needs it to install the APK after Gradle)
2. <project_dir>/android/local.properties exists and sets sdk.dir
3. The directory sdk.dir points at exists on disk

Returns false otherwise so the deploy can skip Android cleanly instead of failing late inside Gradle. Pure of side effects.

@spec build_all(keyword()) :: [:ok | {:error, term()}]

Builds native binaries for all platforms present in the project. Runs Android Gradle build if android/ dir exists. Runs iOS build script if ios/build.sh exists (simulator), or xcodebuild if targeting a physical iOS device via device: opt.

@spec detect_physical_ios() :: String.t() | nil

Returns the UDID of the sole connected physical iOS device, or nil. When exactly one physical device is connected, it can be used automatically. With zero or 2+ physical devices, returns nil.

@spec ios_toolchain_available?() :: boolean()

Returns true when an iOS build is feasible: macOS host with xcrun installed. Linux/Windows always returns false. Pure of side effects.

@spec narrow_platforms_for_device([atom()], String.t() | nil) :: [atom()]

When --device <id> is given, narrow platforms to just the platform the device lives on. Drops Android when the id resolves to an iOS device (sim or physical), drops iOS otherwise.

Public so mix dala.deploy can apply the same narrowing before calling DalaDev.Deployer.deploy_all/1 — otherwise the deployer's per-platform filter_by_device_id complains "No device matched" against the irrelevant platform even though the build itself was correctly targeted.

Returns platforms unchanged when device_id is nil.

@spec narrow_platforms_for_device([atom()], String.t() | nil, (-> [DalaDev.Device.t()])) ::
  [atom()]

Variant that takes an iOS-discovery function so tests (and other callers that already have the device list in hand) can avoid the network-bound IOS.list_devices/0 LAN scan.

The lister is called at most once per invocation; both ios_device? and the physical-UDID format fallback consume the same result.

@spec otp_dir_for_abi(String.t(), String.t(), String.t()) :: String.t()

Returns the OTP directory for the given Android ABI string.