feat(heller): seed transport-facing wire artifacts

[mdheller]

Summary

Seed transport-facing Heller wire artifacts in TriTRPC.

Included

• transport seed note
• protobuf wire surface
• encoded payload manifest with base64 payload examples

Intent

This PR makes the Heller wire siblings visible in the transport repo without claiming final canonical frame vectors.

Explicit non-goals in this PR

• final SERVICE/METHOD binding
• schema/context ID freeze
• canonical frame vectors with nonce fixtures
• parity verification through Rust/Go conformance yet

Follow-on

• derive stable transport IDs where required
• bind specific service/method surfaces
• emit canonical frame vectors and verify byte parity
• align with the storage standards contract family PR