fix(test): stop the suite depending on generated Nuxt types

CI ran zero tests: `[TSCONFIG_ERROR] Failed to load tsconfig` for all 10 files,
every suite failed, and it passed locally the whole time.

oxc resolves the nearest tsconfig for each file it transforms. The root
`tsconfig.json` is a project-references stub pointing into `playground/.nuxt/`,
which only exists after `nuxt prepare` — and CI runs `pnpm test` before
`pnpm dev:prepare`, which I ordered that way on purpose so lint and tests fail
fast. Locally a generated `.nuxt` was always lying around, so the dependency was
invisible. Reproduced by moving `playground/.nuxt` aside; it also means `pnpm test`
never worked from a fresh clone.

Turn tsconfig resolution off for the transform instead of reordering CI. Nothing
under test needs tsconfig-driven semantics — no decorators, no path aliases,
relative imports throughout — so the suite becomes hermetic rather than dependent
on a build artefact, which is what a unit test should be.

A scoped `test/tsconfig.json` alone was not enough: it fixed `test/setup.ts` and
then the imported sources failed instead, each resolving the root stub from its own
directory. It stays for editors, which otherwise have no project covering `test/`,
but it is not what the transform reads.

Verified both ways: with `playground/.nuxt` present and absent, 103 tests pass.

Author: benjamincanac

test/tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "noUncheckedIndexedAccess": true,
+    "verbatimModuleSyntax": true,
+    "skipLibCheck": true,
+    "types": ["vitest/globals", "node"]
+  },
+  "include": ["./**/*.ts"]
+}

vitest.config.ts

@@ -1,6 +1,24 @@
 import { defineConfig } from 'vitest/config'
 
 export default defineConfig({
+  // Transform without consulting any tsconfig.
+  //
+  // oxc otherwise resolves the *nearest* tsconfig per transformed file, and the root
+  // `tsconfig.json` is a project-references stub pointing into `playground/.nuxt/`,
+  // which only exists once `nuxt prepare` has run. So `pnpm test` from a fresh clone
+  // — or in CI, which runs it before `dev:prepare` on purpose so it fails fast —
+  // reported `[TSCONFIG_ERROR] Tsconfig not found` for every file and ran zero tests,
+  // while passing locally purely because a generated `.nuxt` happened to be lying
+  // around. Reproduced by moving `playground/.nuxt` aside.
+  //
+  // Nothing under test needs tsconfig-driven semantics: no decorators, no path
+  // aliases, relative imports throughout. Opting out makes the suite hermetic
+  // instead of dependent on build artefacts. `test/tsconfig.json` still exists, for
+  // editors — it is not what the transform reads.
+  //
+  // `tsconfig` is absent from Vite's `OxcOptions` type but forwarded verbatim to
+  // `transformSync`, hence the cast.
+  oxc: { tsconfig: false } as never,
   test: {
     include: ['test/**/*.test.ts'],
     setupFiles: ['test/setup.ts'],