Rust Observability

Rust observability with tracing, metrics, logs, OpenTelemetry, and production diagnostics. Use when: - User adds logging, tracing spans, metrics, request IDs, or distributed tracing to Rust services - User uses tracing, tracing-subscriber, tracing-opentelemetry, opentelemetry, metrics, prometheus, or axum tracing layers - User debugs missing logs, noisy logs, span propagation, trace IDs, structured fields, or async task visibility - User needs RED/USE metrics, histograms, dashboards, alerts, or SLO instrumentation - User instruments Axum/Tokio/background workers/databases/queues - User asks what to log, what not to log, or how to avoid leaking secrets/PII in telemetry - U…