API: Drive object, typed StreamUrl, tray lock/unlock, Send traits

- Rename DriveSession → Drive across entire codebase
- find_drives() returns Vec<Drive>, find_drive() returns Option<Drive>
- resolve_device() now pub(crate) — internal only
- StreamUrl is now a typed enum (Disc, Mkv, M2ts, Iso, Network, Stdio, Null)
  with scheme() and path_str() accessors, replacing struct of Strings
- Add lock_tray() / unlock_tray() for safe disc access during rips
- Improve reset() with eject cycle that clears LibreDrive stuck state
- Add Send bounds to ScsiTransport and PlatformDriver traits
- DiscOptions uses PathBuf instead of String for device/keydb paths
- Update doc example to use new Drive API

src/disc/encrypt.rs

@@ -17,7 +17,7 @@ impl Disc {
     /// SCSI handshake result — volume ID and bus keys from ECDH authentication.
     /// Only available when scanning from a real drive (not ISO images).
     pub(super) fn do_handshake(
-        session: &mut crate::drive::DriveSession,
+        session: &mut crate::drive::Drive,
         opts: &ScanOptions,
     ) -> Option<HandshakeResult> {
         use crate::aacs::{self, KeyDb};