Created detailed debug tests that reveal:
1. ✅ Our Metadata v1 response structure is byte-perfect
- Manual parsing works flawlessly
- All fields in correct order and format
- 83-87 byte responses with proper correlation IDs
2. ❌ kafka-go ReadPartitions consistently fails
- Error: 'multiple Read calls return no data or error'
- Error type: *errors.errorString (generic Go error)
- Fails across different connection methods
3. ✅ Consumer group workflow works perfectly
- FindCoordinator: ✅ Working
- JoinGroup: ✅ Working (with member ID reuse)
- Group state transitions: ✅ Working
- But hangs waiting for SyncGroup after ReadPartitions fails
CONCLUSION: Issue is in kafka-go's internal Metadata v1 parsing logic,
not our response format. Need to investigate kafka-go source or try
alternative approaches (Metadata v6, different kafka-go version).
Next: Focus on SyncGroup implementation or Metadata v6 as workaround.
