Add support for Reusable Backend Module Files (Importable Utility Files)

In my project, I currently have a backend function that has grown to thousands of lines because there is no way to create reusable module files that other backend functions can import. The result is a “mega-function” that the AI struggles to maintain, refactor, or safely update.

Building smaller independent functions and using invoke is not a viable workaround because of other known invoke-related issues (e.g., the Cloudflare “Request Header or Cookie Too Large” error), which the support team has confirmed will not be addressed at this time. This makes splitting logic across multiple functions risky.

Please add support for non-deployable shared module files that can be imported by backend functions. This would allow a clean architecture, reduce code duplication, and prevent mega-functions from becoming unmanageable.

If this feature is not planned soon, please update the AI instructions so it stops generating helper module files that cannot deploy. These failed deployments create unnecessary errors and friction during development.