Protocol parameter fields (minFeeA, minFeeB, maxTxSize, maxValSize)
lacked fallback defaults, causing "Cannot convert undefined to a BigInt"
when Lucid-Evolution processed them. Added safe defaults sourced from
Vector public testnet and updated deposit values to match. Made
lovelaceToAda() defensive against undefined/null. Added diagnostic
logging to getWalletInfo and getProtocolParameters error paths.
Converted Dockerfile to multi-stage build and added docker-compose.yml
with inline Vector testnet environment config.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
