Support stdlib-style logger arguments

[fallintoplace]

Summary

• teach the shared logging wrappers to accept stdlib-style % arguments and exc_info= while preserving rank0_only= behavior
• cover the wrapper compatibility directly with a hermetic logger test
• cover the HF export worker guarantee with a regression that proves _worker_exception is recorded when the background export fails

Why

HFExportCallback._save_and_upload() logs worker failures with stdlib-style logger arguments. The project logger wrappers only accepted (message, rank0_only=True), so that error path could raise TypeError before _worker_exception was assigned.

I chose to fix the shared wrapper instead of only rewriting the callback call site because the repo already has other callers using the same %-style logging pattern. This keeps the callback guarantee intact and removes the same footgun for those existing call sites too.

Validation

• uvx ruff check /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/utils/log.py /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/utils/log_test.py /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/callbacks/hf_export_test.py
• uvx ruff format --check /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/utils/log.py /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/utils/log_test.py /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/callbacks/hf_export_test.py
• PYTHONPATH=/Users/hoangvu/Code/OSS/cosmos-framework uvx pytest --noconftest /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/utils/log_test.py /Users/hoangvu/Code/OSS/cosmos-framework/cosmos_framework/callbacks/hf_export_test.py -o addopts=