Add systematic tracing for control message encode/decode

[kixelated]

Summary

• Centralize protocol message logging in the Message trait blanket impls for both lite and IETF, replacing 22 scattered trace! calls
• On encode: log the message at TRACE level before encoding
• On decode: conditional path — when TRACE is enabled, capture raw bytes via copy_to_bytes for diagnostics (logged on failure as warn!); when disabled, use the zero-copy buf.take() path with no overhead
• Add trace logging for IETF GroupHeader which implements Encode/Decode directly
• Remove noisy operational trace lines (frame sizes, group lifecycle) that obscured actual protocol messages

Test plan

• just check passes — all tests and linting
• Run relay with RUST_LOG=moq_lite=trace and verify trace output shows encoded/decoded messages
• Verify warn! output on malformed input includes raw bytes at TRACE level

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 5952322e-cc1f-49b6-9038-97f2e2609a34

📥 Commits

Reviewing files that changed from the base of the PR and between 17554ff and 4c1657d.

📒 Files selected for processing (10)

• rs/moq-lite/src/client.rs
• rs/moq-lite/src/ietf/adapter.rs
• rs/moq-lite/src/ietf/group.rs
• rs/moq-lite/src/ietf/message.rs
• rs/moq-lite/src/ietf/publisher.rs
• rs/moq-lite/src/ietf/subscriber.rs
• rs/moq-lite/src/lite/message.rs
• rs/moq-lite/src/lite/publisher.rs
• rs/moq-lite/src/lite/subscriber.rs
• rs/moq-lite/src/server.rs

💤 Files with no reviewable changes (7)

• rs/moq-lite/src/ietf/publisher.rs
• rs/moq-lite/src/server.rs
• rs/moq-lite/src/client.rs
• rs/moq-lite/src/lite/subscriber.rs
• rs/moq-lite/src/ietf/adapter.rs
• rs/moq-lite/src/ietf/subscriber.rs
• rs/moq-lite/src/lite/publisher.rs

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Walkthrough

This pull request consolidates tracing statements across the MOQ lite implementation. It removes multiple tracing::trace! log statements from client, server, publisher, and subscriber control flow paths (totaling removals of 2, 2, 1, 7, 9, and 8 lines across respective modules). Concurrently, it adds trace logging at the message encoding/decoding boundary layer by instrumenting GroupHeader serialization and reworking message decode logic to conditionally validate buffer length, log decoding outcomes, and emit warnings on decode failures. The net effect shifts observability focus from high-level control flow events to lower-level message transformation events.

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main objective: centralizing systematic tracing for control message encode/decode operations across the codebase.
Description check	✅ Passed	The description is directly related to the changeset, detailing the consolidation of trace logging into Message trait impls, conditional TRACE paths, and removal of noisy operational traces.

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