test: await ky create request

[as490024862-cmd]

Summary

• await the Ky POST request before reading the created records
• parse and assert the Ky JSON response
• remove the race that can make the create/list test flaky

Verification

• git diff --check passed
• Bun is not available in the local environment; GitHub Actions should run the project test suite

/claim #2

EVM payout address if supported: 0xa12c4fFe05Fa3355AdE1cC2110F9dAeEfcc7A0c2