fix: default package exports

[userquin]

This PR includes the following changes to the packages/tailwindcss package (check Context):

• fixes the default packages exports for node10 and node16 cjs types
• export types in plugin.ts module, cannot be used with Typescript 5.7
• add "type": "commonjs" to package.json
• add ./lib/util/flattenColorPalette.js variant to package.json exports (publishConfig)

Context
The current version at npm registry has all types broken for all packages exports. The problem seems to be with tsup since it is not applying the .cts hack, all d.ts files using export { X as default };, check https://arethetypeswrong.github.io/?p=tailwindcss%404.0.0 .

With this PR (for context check this PR unjs/unbuild#475 and this md file https://github.com/unjs/unbuild/blob/a011a7831e2004688bf44716f5e9c9377d08ebec/src/builders/rollup/plugins/cjs.md):

This PR includes a new script module that runs after tsup finish building the dist, extracting the default export and applying some replacements in the files including the default export correclty: export = X; and remaining named exports in the default export statement.

About exporting the types in the plugin.ts module, when using TypeScript 5.7 there is an error. Using the following code with any module resolution

import plugin from 'tailwindcss/plugin'

const exportedPlugin = plugin.withOptions(() => {
	return ({ matchComponents }) => {
		matchComponents({
			test: (content: string) => {
				return {
					color: content,
				};
			},
		});
	};
});

export default exportedPlugin;

and building it via tsc -b, there is an error about required annotation:

Using a local tgz from this PR, TypeScript is fine when building the module:

You can generate the local tgz using this PR in the following repository (use packages/plugin): https://github.com/iconify/iconify-tailwind

[userquin]

We should add "type": "commonjs" to the package.json.

[userquin]

We should add "type": "commonjs" to the package.json.

[userquin]

Looks like @tailwindcss/node package also broken, this is the index.d.ts content (index.d.mts with same imports)

Downloaded tgz file from npm registry: https://registry.npmjs.org/@tailwindcss/node/-/node-4.0.0.tgz