fix(plugin-react): use '/' base in bundledDev preamble to fix non-root base paths

[JustInCache]

Summary

Fixes #1190

When using experimental: { bundledDev: true } with a non-root base (e.g. base: "/static/"), the vite:react-refresh-fbm plugin was calling getPreambleCode(base), producing:

import { injectIntoGlobalHook } from "/static/@react-refresh";

Rolldown resolves module specifiers at build time — there is no URL-level base-stripping middleware involved. So /static/@react-refresh never matched the resolveId hook which only handles the exact string /@react-refresh, causing:

[UNRESOLVED_IMPORT] Error: Could not resolve '/static/@react-refresh'

In non-bundled dev mode this worked because the browser fetched the URL and Vite's baseMiddleware stripped the prefix before the request reached the resolve/load hooks.

Fix

Pass '/' instead of config.base to getPreambleCode inside viteReactRefreshBundledDevMode. This produces /@react-refresh directly, which the resolveId hook can match. This is consistent with what virtualPreamblePlugin already does (with the comment "vite dev import analysis can rewrite base").

Test

Added a new e2e playground playground/bundled-dev-base-path with base: '/static/' + experimental: { bundledDev: true } that verifies:

• The page loads without any UNRESOLVED_IMPORT browser errors
• React renders and state updates work correctly

[JustInCache]

@hi-ogawa Can you please review ? Suggest feedback if any !! Thanks