Use when adding instrumentation, OpenTelemetry/OTLP/Collector config, metrics or structured logging, distributed tracing, dashboards, alert rules, or SLOs/error budgets in a touchstone repo — covers the three signals, cardinality discipline, and burn-rate alerting. Invoke before wiring telemetry or paging. NOT the deploy-time infra (Prometheus/Grafana operators, k8s) — that's devops-standards.
