Canditates search issue in @tailwindcss/vite@^4.0.8

This reproduction shows an issue in @tailwindcss/vite@^4.0.8 that breaks the candidates search when the config file (css) is loaded from a package.

In @tailwindcss/[email protected] it works because it uses the Module Graph to find the candidates, but it was replaced with a FS based system in this PR tailwindcss#16631.

Steps

1. run pnpm dev, open the preview a check that the button is loading with Tailwind styles applied.
2. in the package.json, replace "@tailwindcss/vite": "4.0.7" with "@tailwindcss/vite": "4.0.9" and run pnpm i.
3. run pnpm dev, now the button does not have styles applied.

Observations

• Theorically, this could be fixed by using @source, but as seen in node_modules/@ialdama/tailwind-config/styles.css, it does not work.
• This is probably caused by pnpm dependencies structure, as the css file is not really loading from node_modules/@ialdama/tailwind-config/styles.css but rather node_modules/.pnpm/@[email protected]/node_modules/@ialdama/tailwind-config/styles.css.