v2.4.2

The real fix for the macOS helper blanking metrics (v2.4.1 wasn't enough).

Fixed

• v2.4.1 only bounded the helper call, which still left too little of the 1 s adapter budget for the fallback — so a slow powermetrics helper on an M-series Pro/Max kept timing out the whole privileged adapter (removing the helper was the only recovery).
• The adapter now reads in-process first and consults the helper only when the daemon can't read a CPU power rail itself (power.cpu / power.total / power.pkg). On macOS the daemon already has power from SMC/IOReport, so it never calls the helper — running it on Apple Silicon is finally harmless. On an unprivileged Linux daemon there's no in-process RAPL, so the helper is still consulted for it (bounded so a slow one can't hang). GPU power alone doesn't count — a Linux + NVIDIA box still needs the helper for RAPL.