Context

Node already supports sendPairRequest / sendPairRespond. Go can receive pair.* events (#5) but still cannot send them, so a Go agent cannot complete a pairing loop on its own.

Proposal

Add Node-parity pairing support in the Go SDK only:

• header build/parse for pair.request / pair.respond
• SendPairRequest / SendPairRespond on SmtpSender and Client
• round-trip unit tests

No protocol changes.

Intent

I think this gap is worth closing and would like to contribute if the direction looks good. Happy to adjust API details before opening a PR.