Improved v3 callbacks logs

[ZanCorDX]

📝 Summary

• Some logs upgraded to info.
• Metric relay_server_relay_request_latency per relay.
• Some extra timming logged.

💡 Motivation and Context

I'm a control freak.

✅ I have completed the following steps:

• Run make lint
• Run make test
• Added tests (if applicable)

[claude]

Claude finished @ZanCorDX's task in 59s —— View job

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Review of PR #898

• Read diff and changed file
• Analyze changes and provide review

Summary

Clean, small change. A few observations:

1. Breaking metric change: Adding the "relay" label to relay_server_relay_request_latency is a dimension change. Any existing Grafana dashboards or alerts querying this metric without the relay label will break. Make sure downstream consumers are updated accordingly.

2. Latency semantics shifted slightly: relay_latency is now computed from processing_start (captured at function entry) rather than SystemTime::now() at the point of recording. Since the metric moved after auth checks, the "now" is actually earlier than before. The difference is negligible (microseconds of decode + auth), but worth noting the semantic is now "network latency to start of processing" rather than "network latency to point of measurement."

3. Minor formatting nit left as inline comment (missing space before decoding_time).

No bugs or security concerns found. The log level upgrades and per-relay metric breakdown look reasonable for operational visibility.

[claude]

Claude finished @ZanCorDX's task in 56s —— View job

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Review of PR #898

• Read diff and changed file
• Analyze changes and provide review

Summary

The latest commit (1f837d6) fixes the formatting nit from the previous review. The overall diff remains the same otherwise.

The previous review's observations still apply — the main thing to be aware of is the breaking metric change: adding the "relay" label to relay_server_relay_request_latency changes the metric's dimensionality. Any existing Grafana dashboards or alerts querying this metric without the relay label will need updating.

No new issues introduced. LGTM.