Fix macOS build: mark MacScsiTransport as Send

IOKit COM interface pointers are Mach port references, safe to send
between threads. The Send bound added in 0.8.1 broke macOS builds.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libfreemkv"
-version = "0.8.1"
+version = "0.8.2"
 edition = "2021"
 license = "AGPL-3.0-only"
 description = "Open source raw disc access library for optical drives"

src/scsi/macos.rs

@@ -168,6 +168,9 @@ pub struct MacScsiTransport {
     exclusive: bool,
 }
 
+// IOKit COM interface pointers are Mach port references — safe to send between threads.
+unsafe impl Send for MacScsiTransport {}
+
 impl MacScsiTransport {
     pub fn open(device: &Path) -> Result<Self> {
         let dev_str = device.to_str().ok_or_else(|| Error::DeviceNotFound {