gofmt: fix import ordering in client_test.go

Commit

Paulo Gomes3mo ago

Sort the plumbing/protocol import ahead of protocol/packp.

Assisted-by: Claude Opus 4.7 noreply@anthropic.com Signed-off-by: Paulo Gomes paulo@entire.io Entire-Checkpoint: 01KXDKNGABW47M7NK1W0RF1VMR