System Monitor: Add CPU temperature monitoring

[ADCAdams]

Description

Adds real-time CPU temperature monitoring to the System Monitor extension, as suggested in #25555 by @0xdhrv.

Currently no temp monitoring in raycast store!

What's new

• Temperature section in list view — shows CPU average, max, per-sensor die temperature readings, chip model, core count, and color-coded severity status (normal/warm/hot/critical)
• Temperature in menu bar — CPU temperature displayed alongside existing CPU, Memory, Network, and Power metrics
• "Temperature" option in Default Tab preference — users can launch directly to the temperature view

How it works

Reads thermal sensor data via macOS IOKit HID APIs through a lightweight Objective-C binary (tools/temp-reader.m) compiled from source during the build step. No sudo, no kernel extensions, no native Node.js addons. The binary is compiled as a universal binary (arm64 + x86_64) via a prebuild npm script.

Die sensors vs CPU cores

macOS exposes thermal die sensors (e.g. PMU tdie1), not per-core temperature readings. The number of die sensors does not match the CPU core count — for example, an M4 Max has 14 cores but 10 die sensors. The UI clearly labels these and shows the actual core count separately.

GPU temperature

On Apple Silicon, GPU shares the die with the CPU (unified architecture). Separate GPU temperature is not exposed by the hardware. The extension explains this in the detail panel.

Screencast

Screenshots from the standalone version (same UI, now integrated into System Monitor):

Checklist

• I read the extension guidelines
• I read the documentation about publishing
• I ran npm run build and tested this distribution build in Raycast
• I checked that files in the assets folder are used by the extension itself
• I checked that assets used by the README are placed outside of the metadata folder