Platform trait is no longer publicly exported. External code uses
DriveSession only — cannot call unlock, load_firmware, calibrate directly.
- Platform trait: pub(crate) with 3 methods only
- All handlers are private methods on Mt1959
- DriveStatus moved to mt1959 internal struct
- init() has guard: no re-init if already ready
- set_read_speed() has guard: no-op if not calibrated
- Removed open_unlocked() — open() is the only entry
- Removed Platform and DriveStatus from public exports
Prevents: out-of-sequence SCSI commands, double-init, wrong firmware writes.
MattJackson
6456e24bb5