fix(core): use workspace root for path resolution when baseUrl is not set (#34453)

## Current Behavior

When a project-level `tsconfig.json` (e.g., `apps/aurora/tsconfig.json`)
inherits `paths` via `extends` from `tsconfig.base.json` at the
workspace root and no explicit `baseUrl` is set, Nx incorrectly resolves
`./`-prefixed path mappings relative to the project tsconfig directory
instead of the workspace root where the paths were defined.
This causes errors when loading TypeScript config files (e.g.,
`rspack.config.ts`) that import workspace libraries using path aliases:
  NX   Cannot find module './libs/plugins/rspack/src'

`@swc-node/register`'s `readDefaultTsConfig` auto-sets `baseUrl` to
`dirname(tsConfigPath)` (the project directory) when not explicitly
configured, causing SWC to rewrite imports to incorrect relative paths
during transpilation.

  ## Expected Behavior

Path aliases defined in `tsconfig.base.json` (e.g.,
`"@trellis/plugins/rspack": ["./libs/plugins/rspack/src/index.ts"]`)
should resolve relative to the workspace root when no `baseUrl` is
configured.

This is needed so that when using `tsgo` and needing to prefix all paths
with `./` (no more `baseUrl` allowed) the paths are still resolved from
the right spot.

I tested this fix against our codebase on the branch I was trying to
switch to tsgo on and it seemed to work.

  ## Related Issue(s)

Fixes
https://discord.com/channels/1143497901675401286/1471627045694865581

(cherry picked from commit a0e3455)

Author: yharaskrik

packages/nx/src/plugins/js/utils/register.ts

@@ -2,6 +2,7 @@ import { join, sep } from 'path';
 import type { TsConfigOptions } from 'ts-node';
 import type { CompilerOptions } from 'typescript';
 import { logger, NX_PREFIX, stripIndent } from '../../../utils/logger';
+import { workspaceRoot } from '../../../utils/workspace-root';
 import { readTsConfigWithoutFiles } from './typescript';
 
 const swcNodeInstalled = packageIsInstalled('@swc-node/register');
@@ -422,6 +423,21 @@ function readCompilerOptionsWithSwc(tsConfigPath) {
   // @swc-node/register filters the files to transpile based on it, but it can be limiting when processing
   // files not part of the received tsconfig included files (e.g. shared helpers, or config files not in source, etc.).
   delete compilerOptions.files;
+
+  // @swc-node/register's readDefaultTsConfig auto-sets baseUrl to the
+  // dirname of the tsconfig when not explicitly configured. This is incorrect
+  // when paths are inherited via "extends" from a parent tsconfig at a
+  // different directory level (e.g., tsconfig.base.json at workspace root),
+  // because SWC will resolve "./"-prefixed paths relative to the wrong
+  // directory. Use the workspace root as baseUrl in that case.
+  // baseUrl will not be configured when using newer versions of TypeScript like `tsgo`.
+  if (compilerOptions.paths) {
+    const { options: tsOptions } = readTsConfigWithoutFiles(tsConfigPath);
+    if (!tsOptions.baseUrl) {
+      compilerOptions.baseUrl = workspaceRoot;
+    }
+  }
+
   return compilerOptions;
 }