Monitors instantaneous CPU utilization (the soft beta_vcpus signal).

Samples /proc/stat every 23 ms and reports the busy fraction (0.0..1.0, normalized across all cores) between consecutive reads - never the load average, which has different semantics. The first read only establishes a baseline (:skip). Readings are smoothed with a 30-second time constant (sampling fast only de-noises the filter; the smoothing window is set by tau).