Agent Skills: ring:using-lib-observability

Using lib-observability v1.1.0, Lerian's OpenTelemetry foundation (lib-commons, lib-systemplane, lib-streaming depend on it), in two modes. Sweep Mode detects DIY zap/slog logging, raw OTel metrics, hand-rolled redaction, and hard-coded attribute strings. Reference Mode catalogs the log, metrics, zap, redaction, and constants packages. Go-only. Skip for non-Go or assert/runtime/tracing.