M1: persistent vault, local unlock key, sync client, test vectors

kv-store: SQLite (bundled) and in-memory Store holding only ciphertext
envelopes, with base copies for three-way merges and a 10-version history.

kv-ffi: VaultCore::open(path); persisted account record; local unlock key
(enable/unlock_with_local_key/disable); async sync API (configure_server,
set_device_signer, register_account, login, sync_now, logout, devices);
DeviceSigner foreign trait; IntegrityAlarm/PinMismatch/... error variants.

kv-sync: reqwest + rustls (TLS 1.3 only, ring) with SPKI pinning; OPAQUE
client on kv-proto's OpaqueSuite; RFC 9421 signing per kv_proto::httpsig;
pull/push with If-Match, field-level three-way merge, edit-beats-delete;
signed manifest (canonical CBOR, Merkle root, prev chain, Ed25519) with
rollback/fork/Merkle checks as hard integrity alarms. Tested against a
wiremock fake server, plus an #[ignore] test against kestrove-server.

kv-crypto: gen-vectors example and tests reproducing kestrove-spec/vectors.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/kv-ffi/Cargo.toml

@@ -18,8 +18,18 @@ path = "src/bin/uniffi-bindgen.rs"
 kv-proto.workspace = true
 kv-crypto.workspace = true
 kv-model.workspace = true
+kv-store.workspace = true
+kv-sync.workspace = true
+serde.workspace = true
+hkdf.workspace = true
+sha2.workspace = true
+tokio = { workspace = true }
 uuid.workspace = true
 thiserror.workspace = true
 serde_json.workspace = true
 zeroize.workspace = true
-uniffi = { workspace = true, features = ["cli"] }
+uniffi = { workspace = true, features = ["cli", "tokio"] }
+
+[dev-dependencies]
+kv-sync = { workspace = true, features = ["test-server"] }
+tempfile.workspace = true