InputUtxo gains an `assets: BTreeMap<String, u64>` field matching
aldabra-chain::Utxo's shape (`policy_id_hex(56) || asset_name_hex`
key). new AssetSpec type for the recipient asset list.
asset-aware select_utxos:
- phase 1: per-asset greedy by holding size, pulls UTXOs containing
each requested asset until coverage ≥ target
- phase 2: ada-only greedy to top up lovelace need
this preserves the prior ada-only behavior when assets list is empty.
build_signed_payment_with_assets / build_unsigned_payment_with_assets
build outputs with .add_asset() for each requested + each leftover
(change-side). guards: token-bearing change must hold ≥ min_utxo
ADA — surfaced as a clearer error than letting the chain reject a
sub-min output.
cold-sign flow (phase 2.6):
- new tools wallet.send.unsigned (returns {cbor_hex, summary} json
for human review + cold-signer consumption) and
wallet.submit_signed_tx (takes hex-encoded signed cbor → submit).
- PaymentSummary now carries send_assets + change_assets vecs so the
human reviewer can spot accidental token transfers.
- summary.tx_hash is the predicted body hash; signed CBOR will hash
to the same value (signature is over the body, not the cbor wrapper).
helpers: hex_encode/decode, parse_policy_id, parse_asset_name,
split_asset_key. mcp side defines its own McpAssetSpec with
schemars::JsonSchema derive so the schemars dep doesn't bleed into
the security-boundary core crate.
48 unit tests (was 41). new coverage: asset-aware selection (greedy +
missing-asset error), policy/asset-name parsers, multi-asset cbor
build, change-asset summary correctness.
phase 2.7 (live preprod smoke against funded wallet) procedure
documented in memory/spec-aldabra-buildout.md; needs cobb's faucet ada.