Server logging via stdout/stderr redirection

[pjin-nvidia]

Describe the bug

Currently, server logs are not propagated/displayed during normal operation or upon server setup failure. We should redirect stdout and stderr for servers started the normal way (Q: what about the _test_single path of server startup?).

https://github.com/NVIDIA-NeMo/Gym/pull/477/files#diff-fdaac7ce2e22655eb355910ca4f95f8de1be2e8986b3e0ee6bc157bd721153b4R95-R117

Steps/Code to reproduce bug

Please list minimal steps or code snippet for us to be able to reproduce the bug.

A helpful guide on on how to craft a minimal bug report http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports.

Expected behavior

A clear and concise description of what you expected to happen.

Configs NeMo Gym (e.g. via ng_dump_config) or RL training framework config files.

Environment details

Otherwise, please provide:

• OS version
• Python version
• uv pip list output

Additional context

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