Prevent log loss in idle/shared pre-tracing paths by using `info_or_print!`-style macros

[kimhanbeom]

Summary

Some idle-mode and idle-shared code paths can run before the tracing dispatcher is initialized.
In those paths, direct info!, warn!, and error! calls may not be visible, which hurts operational observability.
Please switch those logs to info_or_print!, warn_or_print!, and error_or_eprint! so logs remain visible regardless of tracing initialization state.

Background

init_tracing() is executed inside run() after configuration loading. Therefore, at the point when the process enters idle mode, tracing may not have been initialized yet.

The following events can occur during idle mode and therefore require pre-tracing log visibility:

• TLS reload (SIGHUP) and Shutdown (SIGINT/SIGTERM): include all related code paths from signal registration/reception to main-loop handling and idle-mode transition/exit behavior.

Scope

• src/logging.rs
  • If needed, add a warn_or_print! macro with the same fallback behavior as info_or_print! and error_or_eprint!.
• Replace direct info!/warn!/error! in idle-only or idle-shared paths that may run pre-tracing

Acceptance Criteria

• In pre-tracing state, logs from the targeted idle/shared paths are still printed to stdout/stderr.
• With tracing initialized, logs continue to go through tracing as before.
• TLS reload and shutdown control flow remains unchanged.
• No behavioral regression; build/tests pass.

[kimhanbeom]

This issue has been marked as blocked so it can be resolved at the same time as the shutdown handling changes introduced in #302.