Add macOS SCSI support via IOKit SCSITaskDeviceInterface

IOKit backend for macOS optical drives. Accepts BSD device paths
(/dev/disk2), walks IORegistry to find authoring device, sends
SCSI commands through SCSITaskDeviceInterface COM vtable.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libfreemkv"
-version = "0.3.0"
+version = "0.3.1"
 edition = "2021"
 license = "AGPL-3.0-only"
 description = "Open source raw disc access library for optical drives"
@@ -25,3 +25,6 @@ zip = { version = "2", default-features = false, features = ["deflate"] }
 [target.'cfg(target_os = "linux")'.dependencies]
 libc = "0.2"
 
+[target.'cfg(target_os = "macos")'.dependencies]
+libc = "0.2"
+