[nau]

Summary

Bumps scalus from ^1.4.1 to ^1.5.0 in @meshsdk/core-cst, @meshsdk/scalus-emulator and @meshsdk/transaction (dev dependency). The lockfile changes only the scalus entries.

What Mesh gets with 1.5.0 (full notes: https://github.com/scalus3/scalus/releases/tag/v1.5.0):

• Emulator as a small node: a mempool, real blocks, forks and rollback(n). getTxStatus / awaitTx report pending, confirmed, dropped or rolled-back transactions.
• Epoch boundary: stake snapshots, rewards, pool retirement, and the expiry, ratification and enactment of governance proposals.
• Ledger error names: emulator.ledgerFailures(tx) lists every ledger failure by its cardano-ledger name, for example MissingRedeemers.
• Conway governance rules in the Emulator: committee, constitution, DRep and vote checks, as on a node.

Test change

The Emulator now applies the Conway GOV rule, so a vote from a committee member who is not in the committee fails with UnelectedCommitteeVoters, as on a node. The CC vote test in tx.test.ts now starts the emulator with the wallet's key as a sitting committee member, with itself as the authorized hot key (EmulatorOptions.committee and committeeHotKeys, new in 1.5.0). No library code changes.

Tests

After npm run build:mesh, all pass:

package	tests
mesh-core-cst	183, plus 16 under the Scalus (ESM) config
mesh-transaction	305 (38 suites)
mesh-scalus-emulator	24
mesh-wallet, mesh-x402, mesh-contract, mesh-core	34, 98, 1, 1
npm run test:scalus-packages	ESM, CJS, declarations, browser

Notes for other open PRs

• feat: add @meshsdk/tx-emulator for simulating transactions on a local ledger #858 (@meshsdk/tx-emulator) still pins scalus ^1.3.0; it can take ^1.5.0 and use the new chain features directly.
• Behaviour changes in 1.5.0 that a Mesh user of the Emulator may notice: Emulator.create without treasury now starts with the mainnet treasury, not 0; the Emulator rejects a PlutusV3 transaction that spends and references the same UTxO, and votes by an unregistered DRep.