Migrate from standard log to structured logging

[myselfBZ]

Proposed change: replace the current log usage with structured logging (e.g. leveled fields, consistent context, machine-readable output). This would improve observability and debugging without changing runtime behavior.

Before starting work, I want to confirm that this direction aligns with the project’s goals. If approved, I’ll open a PR that incrementally migrates existing logs and keeps the diff contained and reviewable.