T2.1 — Add `SignalMessage::TransportFeedback`

Status: Pending Review Agent: Kimi Code CLI Started: 2026-05-11T17:00Z Completed: 2026-05-11T17:04Z Commit: (see git log) PRD: ../PRD-transport-feedback-bwe.md

What I changed

crates/wzp-proto/src/packet.rs — Added TransportFeedback variant to SignalMessage:

TransportFeedback {
    #[serde(default)] version: u8,
    stream_id: u8,
    acked_seqs: Vec<u32>,
    nacked_seqs: Vec<u32>,
    remb_bps: u32,
    recv_time_us: u64,
}

crates/wzp-proto/Cargo.toml — Added bincode = "1" to [dev-dependencies] for forward-compat serialization tests.

Why these choices

#[serde(default)] on version ensures old senders that omit the field deserialize cleanly (version = 0). bincode is already used elsewhere in the workspace (e.g., wzp-crypto tests), so adding it as a dev-dependency carries no supply-chain risk.

Deviations from the task spec

None.

Verification output

$ cargo test -p wzp-proto transport_feedback
running 2 tests
test packet::tests::transport_feedback_roundtrip ... ok
test packet::tests::transport_feedback_default_version ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 113 filtered out; finished in 0.00s

Test summary

Tests added: 2
- transport_feedback_roundtrip — JSON + bincode serialization/deserialization
- transport_feedback_default_version — verifies omitted version field defaults to 0
Tests modified: 0
wzp-proto test count: 115 (was 113 before T2.1)
cargo clippy -p wzp-proto --all-targets -- -D warnings: pass
cargo fmt --all -- --check: pass

Risks / follow-ups

No production code consumes TransportFeedback yet — T2.2/T2.3 will wire the BWE layer to produce and ingest it.

Reviewer checklist (filled in by reviewer)

Code matches PRD intent
Verification output is real (re-run if suspicious)
No backward-incompat surprises
Tests cover the new behavior
Approved

2.0 KiB Raw Blame History

T2.1 — Add SignalMessage::TransportFeedback