radar_trace 0.1.0

Pure-Dart tracer framework with monotonic spans, log-linear latency histograms, Zone-based async nesting, and a lossless outlier ring.

0.1.0

• Initial release: Span model, LatencyHistogram, OutlierRing, TraceRecorder, TraceSnapshot, Tracer façade with Zone-based nesting.
• Added per-key call metrics to SpanKeyStatsSnapshot: firstStartMicros, lastStartMicros, avgInterCallIntervalMicros (null when count < 2), callsPerSecond (null when count < 2 or window is zero), meanMicros, maxMicros, totalMicros — all exact (no bucket approximation).