fix(sdk-core): enforce recipient verification in ECDSA TSS signing

[mrdanish26]

Ticket: WCN-151

Summary

Closes the default-path vulnerability in ECDSA TSS signing (WCN-151 Phase 3)
where a compromised BitGo API server could swap signableHex undetected.

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The Vulnerability

Both EcdsaUtils and EcdsaMPCv2Utils defaulted txParams when absent:

// Before — vulnerable
txParams: params.txParams || { recipients: [] }

When txParams is not passed (Classic UI pending approval, Express),
verifyTransaction() receives an empty recipients list and skips all
address and amount verification. A compromised API server could swap
signableHex to redirect funds without the SDK detecting it.

Attempted 3 times ([#8462], [#8539], [#8658]) and reverted each time.
Root cause of prior failures: coin-level verifyTssTransaction overrides had
stale hardcoded arrays missing staking types, so the guard threw for legitimate
staking transactions even when resolveEffectiveTxParams passed them through.

---
14-Day Dry-Run (2026-05-21 to 2026-06-03)

Two sources queried — Loki is authoritative (Prometheus undercounts due to
in-memory counter resets across pod restarts):

Loki — wallet-platform + wallet-platform-admin-nocluster — 444 entries

┌────────┬────────────────┬───────────┬─────────────┬──────────────────┐
│  Coin  │    tx_type     │ Loki hits │ Kibana hits │      Status      │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ canton │ enableToken    │ 206       │ 76          │ already exempt   │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ sol    │ customTx       │ 106       │ 50          │ already exempt   │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ canton │ createAccount  │ 89        │ 34          │ added in this PR │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ sol    │ enableToken    │ 22        │ 10          │ already exempt   │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ canton │ transferAccept │ 8         │ 7           │ added in this PR │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ bsc    │ tokenApproval  │ 6         │ 0*          │ already exempt   │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ hash   │ contractCall   │ 3         │ 0*          │ added in this PR │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ ada    │ pledge         │ 2         │ 1           │ added in this PR │
├────────┼────────────────┼───────────┼─────────────┼──────────────────┤
│ apt    │ customTx       │ 2         │ 0*          │ already exempt   │
└────────┴────────────────┴───────────┴─────────────┴──────────────────┘

*Kibana index (logstash-beat-wallet-platform-prod*) does not cover the
wallet-platform-admin-nocluster app — those hits only appear in Loki.

hash/contractCall — 3 Loki hits, all 3 are signing rounds for the same
txRequest (71cc470c), i.e. 1 unique transaction. Via
v2.admin.txrequest.signatureshare.bulk.create, user caseykampa@bitgo.com,
2026-06-02 19:30–19:33 UTC. hash (Provenance) uses secp256k1 — ECDSA
enforcement would block this without the exemption.

ada/pledge — stakingRequestId is not set on the Trust custodial path;
must be in the explicit set, cannot rely on the staking bypass.

Zero hits from payment, fanout, vote, defi-deposit, defi-redeem
in both Loki and Kibana across all 14 days. ECDSA enforcement is safe.

---
Changes

recipientUtils.ts (new) — single source of truth for the 27-type
NO_RECIPIENT_TX_TYPES set and resolveEffectiveTxParams(). Falls back to
intent.recipients, resolves txType from intent.intentType when
txParams.type is absent, propagates stakingRequestId, and throws
InvalidTransactionError only when no recipients and no exemption applies.

ecdsa.ts + ecdsaMPCv2.ts — replace the vulnerable default:

// After — secure
txParams: resolveEffectiveTxParams(txRequest, params.txParams)

bsc.ts, bscToken.ts, xdc.ts, xdcToken.ts, evmCoin.ts,
abstractEthLikeNewCoins.ts — replace stale hardcoded arrays (4–7 types
each, all missing staking types) with NO_RECIPIENT_TX_TYPES.has(txParams.type)
plus stakingRequestId bypass.

iBaseCoin.ts, baseTypes.ts, iWallet.ts — add stakingRequestId?: string
to TransactionParams, PopulatedIntent, and PrebuildTransactionResult.

---
Out of Scope

- EdDSA enforcement — Phase 4, separate PR
- bitgo-ui TssTxRecipientSource.Explicit call sites — Phase 3b

---
Test Plan

- yarn test --filter=@bitgo/sdk-core passes (recipientUtils + ecdsaMPCv2 tests)
- BSC delegate/undelegate — no missing txParams regression
- EVM tokenApproval, consolidate — no regression
- Canton createAccount, enableToken — no regression
- Normal ETH/BTC send with recipients — address + amount still verified
- Post-deploy Loki: |= "TSS signing with no intent recipients" — zero new hits within 24h

[linear-code]

WCN-151