Replace custom monitoring logic with tracing levels

[adamski]

Custom logic has been implemented to enable/disable monitoring. This is redundant, as the tracing crate, combined with the RUST_LOG environment variable, already provides this functionality out of the box. Using the standard approach is simpler and more powerful.

To fix:

• Remove the custom monitoring enable/disable flags and logic.
• Control monitoring output by setting RUST_LOG to the desired level (e.g., RUST_LOG=debug, RUST_LOG=info).
• Ensure all monitoring code uses tracing levels correctly.

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Migrated from Linear: REP-11