When's importing a file from a project reference, Volar doesn't redirect to the source file for completion, type checking, like the builtin tsserver support does: https://www.typescriptlang.org/tsconfig#disableSourceOfProjectReferenceRedirect. This allows type checking & auto completion, etc. To work in VS Code even before you build the dependent project's .d.ts.

Steps to reproduce

1. Clone https://github.com/segevfiner/vite-issue-1815
2. pnpm i
3. Open the project in VS Code.
4. Open apps/web/src/App.vue, check the offending import line which will warn with

Output file '.../vite-library-test/packages/foo-lib/src/index.d.ts' has not been built from source file '.../vite-library-test/packages/foo-lib/src/index.ts'.ts(6305)

5. Open apps/web/src/main.ts, notice there is no error for the same import there.

P.S. Why do I need https://github.com/segevfiner/vite-issue-1815/blob/229ca43e34e86b4d7bbb14940f7e5b00ca90dc42/apps/web/tsconfig.app.json#L10-L11 shouldn't this be figured out from the dependency between the projects? Is this TypeScript possibly getting confused due to the tsconfig.json not really specifying the actual output paths and them not matching with what Vite outputs?