Fix/nonblocking athena udp logging

[gripeyes]

Compatibility:

patch

Issues/Tickets:

OpenMoonRay/openmoonray#276
#8

Release notes comment:

Prevented unavailable Athena UDP logging from blocking or aborting Arras rendering sessions.

Comments for the reviewer:

This PR is stacked on #8, which already provides the required Boost.Asio modernization. Once #8 merges, this PR will contain only the non-blocking logging change.

Athena UDP logging runs inline from latency-sensitive Arras message paths. When no local syslog endpoint is draining port 514, a blocking send or repeated send errors can interrupt scene updates.

This change:

• configures the Athena UDP socket as non-blocking
• uses Boost.Asio’s non-throwing error_code send overload
• drops best-effort telemetry when the destination is unavailable or the send buffer is full
• removes the retry loop that could delay message delivery

The historical Boost resolver change was excluded because it is already covered by #8. An intermediate macOS EINVAL exception workaround was also excluded because this final implementation supersedes it.

Umbrella validation PR:
OpenMoonRay/openmoonray#276

Houdini 22 build notes:
https://github.com/gripeyes/openmoonray/blob/test/houdini22-clean-build/building/macOS/Houdini22_build_notes.md

Look or scene setup change:

No expected look change.

Special notes for production:

Athena UDP telemetry is best-effort and may be dropped when its destination is unavailable rather than delaying rendering.

Attention/Reviewers:

AI Assisted Development:

Assisted-by: OpenAI Codex / GPT-5.6

Checklist:

• Documentation has been updated.
• Includes new unit tests.
• Includes new RATS tests.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: gonsolo / name: Andreas Wendleder (e350aa1)
• ✅ login: gripeyes / name: Jakub Svoboda (150d736)

[gripeyes]

Hi @gonsolo , if you could sign the CLA so this PR can get merged smoothly it'd be amazing!

[gonsolo]

I signed this long ago but since most of my PRs were ignored I stopped looking.

[gripeyes]

Ahh, idk why the resign isn't picking up your previous one tbf. I'm not from dreamworks/moonray team fyi, just a contributing to open-source as well. I'll leave it up to them.

(Noticed things moving forward a bit, so I started pushing some stuff further from my older massive PR)

[gonsolo]

I signed again, I think it's required again because they moved to the Academy Foundation.

[gripeyes]

Thanks, we're in orange now. Some thing have changed w/ ASF when it come to the sign-offs. Let's see how it goes & if it gets merged, thanks for the contribution eitherway! :)

[gonsolo]

#8 is merged now. @gripeyes, if you rebase after this and force push the DCO should work (I saw your signoff on your patch).

[gripeyes]

Thanks for letting me know @gonsolo ! @jlanz a small follow up from #8