Fix deploy output min ADA: apply Babbage/Conway UTxO entry overhead formula

[Copilot]

The deploy transaction output was underfunded because the SDK's calculateMinimumUtxoLovelace omits the 160-byte UTxO entry overhead mandated by the Babbage/Conway ledger formula, and seeding it with Assets.zero produces a CBOR size 4 bytes smaller than the actual output (0 lovelace = 1-byte CBOR vs. any typical min value ≥ 65536 = 5-byte CBOR). Result: 1,913,640 lovelace submitted vs. 2,620,480 required.

Changes

• src/mint.ts — Replace direct calculateMinimumUtxoLovelace call with a two-step calculation:
  • Pass coinsPerUtxoByte: 1n to obtain the raw CBOR byte count rather than a lovelace amount
  • Use Assets.fromLovelace(1_000_000n) as a placeholder so the lovelace field serializes with the same 5-byte CBOR encoding as the final value
  • Apply the correct ledger formula manually: (cborSize + 160n) * coinsPerUtxoByte

const cborSize = await Effect.runPromise(
  calculateMinimumUtxoLovelace({
    address: blackholeAddr,
    assets: Assets.fromLovelace(1_000_000n),
    scriptRef: script,
    coinsPerUtxoByte: 1n,
  })
);
const minLovelace = (cborSize + 160n) * coinsPerUtxoByte;
// (448 + 160) × 4310 = 2,620,480 ✓

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