Fix macstats native addon load in GPU API route (Apple Silicon)

[wasawi]

Problem

On Apple Silicon, the GPU monitor in the UI always shows 0 for temperature, utilization, power, and fan speed.

The /api/gpu route loads the native macstats addon with:

import { createRequire } from 'module';
...
const nativeRequire = createRequire(import.meta.url);
const ms = nativeRequire('macstats');

When next build bundles the server route, it strips the createRequire import (the minified output becomes let a=(void 0)("macstats")) and rewrites import.meta.url to an internal bundle path. So the require throws (TypeError: (void 0) is not a function, or MODULE_NOT_FOUND), the catch swallows it with console.warn('macstats not available', ...), and every stat falls back to 0.

The addon itself is installed and working — require('macstats') succeeds outside the bundle.

Fix

Reach createRequire through process.getBuiltinModule('module') — a runtime call the bundler cannot strip (Node ≥ 22.3; the UI ships Node 23) — and resolve from process.cwd() (the ui/ folder, which is the server's working directory) so node_modules/macstats is found reliably:

const nativeRequire = process.getBuiltinModule('module').createRequire(process.cwd() + '/package.json');
const ms = nativeRequire('macstats');

Verification

On an M3 Max, /api/gpu before the fix returned temperature: 0, utilization.gpu: 0, power.draw: 0 plus a macstats not available warning on every request. After the fix it returns live values during a training run:

{"temperature":72,"utilization":{"gpu":100,"memory":79},"power":{"draw":20.49}}

with zero warnings.

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