feat(monitor): show Apple Silicon power draw (#1980)

* feat(monitor): show Apple Silicon power draw

Merge Energy Model channels into the existing IOReport sampler so GPU usage and power share one subscription and delta. Carry nullable CPU, GPU, ANE, and package watts through the live snapshot and show the capability-gated Power panel.

* fix(monitor): preserve detected power capability

Keep the Power panel mounted across transient empty ticks and avoid subscribing to Energy Model channels on Intel Macs.

* fix(monitor): preserve power panel preferences

Keep explicit persisted visibility selections when adding the Power panel, and retain the last valid GPU usage across power-only or invalid IOReport ticks while power continues to report per-tick nulls.