{
  // Test-infra tsconfig used ONLY by vitest's `test.typecheck` pass (Finding #1).
  // The build tsconfig (`tsconfig.json`) scopes the compiler to `src/**` with
  // `rootDir: ./src`, so it never type-checks the `test/` tree. This config
  // inherits the same strict compiler options but widens the file set to the
  // type-test files so `vitest run` can run `tsc` over them. It is NOT used by
  // `npm run build` (that still uses `tsconfig.json`), so it has no effect on the
  // shipped output.
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "noEmit": true,
    "rootDir": "."
  },
  "include": ["test/**/*.test-d.ts", "src/**/*"]
}