- ApiVersions v0 response: remove unsupported throttle_time field
- Metadata v1: include correlation ID (kafka-go transport expects it after size)
- Metadata v1: ensure broker/partition IDs consistent and format correct
Validated:
- TestMetadataV6Debug passes (kafka-go ReadPartitions works)
- Sarama simple producer unaffected
Root cause: correlation ID handling differences and extra footer in ApiVersions.