Expose the LibreDrive profile catalog as a curated public API on `ld`:
`ld::profiles()` returns the `Profiles` object (with `.get(drive_id)`) and
`ld::profile(filter)` finds one — the catalog of supported drives, queried
without unlocking. The unlock mechanism (firmware blobs, upload sequence, CDB
wire format) stays private; `LibreDrive` is pub(crate), reached only via
`all_unlockers()`.
The unlock-handshake wire format the bdemu test-emulator needs to impersonate a
drive (`UNLOCK_MARKER`, `is_unlock_read_buffer`) is behind a non-default
`emulation` feature; the `cdb` module compiles only under it. Rename the
`ScsiError` error variant to `Scsi` (matches css), gate the test-only
`load_bundled` and `SCSI_STATUS_CHECK_CONDITION`. Clippy-clean in both feature
configs; 86/89 tests pass.
Stage 2: the AACS host-certificate handshake (the AKE + bus-key derivation +
P-160/P-256 EC crypto, ~2050 lines) moves out of libfreemkv into the
self-contained src/aacs module, with its own error type (the Aacs* failure
points + structured ScsiError) and an aes_ecb_decrypt helper. AacsCert impls
crate::Unlocker — matches DiscKind::Aacs, runs run_cert_handshake against the
host certs the consumer passes via UnlockCtx, and returns Unlocked { vid,
bus_key }. collect_host_certs stays in libfreemkv (it reads keysources). The
SCSI contract gains ScsiSense + the AACS/REPORT-KEY opcodes. libfreemkv is
untouched (still green); it rewires onto this in stage 4.
72 tests pass (the handshake brought its full EC-crypto test suite).
Matthew Jackson