fix(vite): resolve workspace css specs to /@fs before ?inline transform - #11474

PR Checklist

• The PR title follows our guidelines.
• Issue filed: vite: workspace CSS imports served to device with __vite__updateStyle (undefined at runtime) #11472
• CLA signed.
• All existing tests are passing — see testing note.
• Tests for the changes are included — see testing note.

What is the current behavior?

The .css branch of the /ns/m route compiles the stylesheet via sharedTransformRequest(${spec}?inline), where spec is the workspace-root-relative URL emitted by the pipeline (e.g. /packages/ui/src/theme/tokens.css). A root-relative URL only resolves under Vite's configured root, so for a monorepo workspace file the transform is denied, the branch silently falls through, and the device receives Vite's DOM-oriented CSS module:

TypeError: undefined is not a function — __vite__updateStyle(...)

(boot fails; the helper doesn't exist on NativeScript)

What is the new behavior?

The CSS branch anchors spec to the real file via /@fs/<root>/<spec> (probing project root first, then the monorepo workspace root) before the ?inline transform — the same /@fs resolution the module pipeline below already uses. In a monorepo the inline compile now succeeds and the device gets export default "<css>" + the __NS_REGISTER_CSS__ bridge call.

Fixes #11472.

Testing note

This code sits in the dev-server route handler, above the unit-testable helper layer — a spec would need a running ViteDevServer with the NS plugin. Verified via a minimal standalone repro exercising the exact transform gap on vite@8.3.0: https://github.com/aleclarson/repro/tree/nativescript-11472 — and end-to-end: this exact change (as a pnpm patch on 8.0.11) unblocked an HTTP-ESM dev boot that previously 404'd/fell through.