pub fn init_meter() -> Option<SdkMeterProvider>Expand description
Initializes OpenTelemetry metrics SDK if OTEL_EXPORTER_OTLP_ENDPOINT is set.
Returns Some(provider) if initialization succeeds, or None if:
- The env var is unset (noop, zero overhead)
- The exporter fails to build (logs warning, graceful failure)
The provider is registered globally via opentelemetry::global::set_meter_provider.