Some Linux setups trigger detect-libc's spawnSync('getconf') fallback
when process.report does not expose glibcVersionRuntime, breaking
tailwindcss under the Node permission model. Add AllowChildProcess
mirroring AllowAddons/AllowWorker, default to ["tailwindcss"], and
emit --allow-child-process accordingly.
Fixes#14824
Add security.node.permissions config to run Node tools (PostCSS, Babel,
TailwindCSS) under Node's permission model, restricting file system access
to the working directory by default.
The binary resolution is simplified to node_modules/.bin → PATH (npx removed).
For both locations, the actual JS entry point is resolved via symlinks (macOS/Linux)
or by parsing npm wrapper scripts (Windows .cmd), then executed as
"node --permission --allow-fs-read=<path> --allow-fs-write=<path> <script>".
Users can opt out by removing "node" from security.exec.allow.
Closes#7287
Bjørn Erik Pedersen