@spec android_otp_dir(String.t()) :: String.t()

Returns the cached Android OTP directory path (may not exist yet).

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

Reads the Elixir vsn from otp_dir/lib/elixir/ebin/elixir.app, or nil.

@spec ensure_android(String.t()) :: {:ok, String.t()} | {:error, term()}

Ensures the Android OTP release is cached. Returns {:ok, path} or {:error, reason}.

@spec ensure_ios_device() :: {:ok, String.t()} | {:error, term()}

Ensures the iOS device OTP release is cached. Returns {:ok, path} or {:error, reason}.

@spec ensure_ios_sim() :: {:ok, String.t()} | {:error, term()}

Ensures the iOS simulator OTP release is cached. Returns {:ok, path} or {:error, reason}.

@spec ios_device_otp_dir() :: String.t()

Returns the cached iOS device OTP directory path (may not exist yet).

@spec ios_sim_otp_dir() :: String.t()

Returns the cached iOS simulator OTP directory path (may not exist yet).

@spec warn_on_elixir_skew(String.t()) :: :ok

Warns (does not fail) when the build's Elixir minor version differs from the Elixir bundled in the device OTP runtime at otp_dir.

This is the Enum.__in__/2 class of breakage: the in operator and other macros expand differently per Elixir minor, so beams compiled by 1.20 call functions a 1.19.5 runtime lacks → :undef at boot → black screen with no obvious cause. Warning (not failing) is deliberate: rc/patch transitions are common and usually fine, and a hard fail would block legitimate builds — but a loud warning would have turned that debugging saga into one line.