Convert all unstructured format-string logging (tracing::error!("msg: {}", var))
to structured field format (tracing::error!(error = %e, "msg")) across route
handlers and key rotation. Strip response text bodies from error messages in
scoped key mint/revoke paths to prevent potential PII (key material) from
appearing in logs.
The core structured JSON logging infrastructure (tracing-subscriber JSON layer,
request ID generation via UUIDv7, pod_id from POD_NAME env, telemetry middleware
span with request_id/pod_id/method/path) was already in place from prior work.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>