extraEntries is defined in config.clientlibs but incorrectly read from config.postcss

[Hugoer]

The new extraEntries configuration has been correctly defined under the config.clientlibs object. However, it is currently being accessed as config.postcss.extraEntries in the codebase. This leads to incorrect behavior or a misinterpretation of the configuration source.

Proposed solution:
Update the following files to read from config.clientlibs.extraEntries instead of config.postcss.extraEntries:

tasks/clientlibs.js
utils/renderClientLibs.js

This will ensure consistency with the intended configuration structure and prevent potential confusion or misconfiguration in the future.

[Hugoer]

Hi team,

Thanks again for resolving the issue with the incorrect config path.

As a follow-up, there's now a real need to change the extraEntries field from an object to an array. This change is important to better support Webpack's advanced optimization configurations—particularly when generating separate files like runtime, chunks, and enabling treeshaking.

These setups can produce multiple output entries that need to be handled in a specific order or allow duplicate keys (e.g., for splitting or grouping), which a plain object structure can't support effectively. Using an array will provide the flexibility and control needed for these use cases.

Can you please update the structure and any related logic accordingly? 💜

Let me know if any clarification is needed!

Thanks!