Module metrics 

Core metrics types for fabric observability.

All types use atomics and work in no_std environments. The FabricMetrics singleton collects system-wide counters and gauges.

Structs

FabricMetrics

Global fabric metrics registry.

MetricCounter

Monotonically increasing counter (atomic u64).

MetricGauge

Current-value gauge (atomic i64).

MetricHistogram

Fixed-bucket latency histogram.