How does one typically implement a "Library"?

I have several MATLAB projects that I reuse frequently. Often I want to take functions or classes from multiple projects and use them in a new one—essentially creating a shared "library" of code.

What’s the best practice for organizing and reusing code across projects?

These are the approaches I’ve considered, and their issues:

• Copying code into the new project – easy at first, but hard to maintain when the original code changes.
• Adding project folders to the MATLAB path – works, but can lead to name conflicts if different projects contain files/functions with the same name.
• Namespace (+folder) packages – solves name conflicts and keeps things organized, but scripts inside a namespace can't automatically see other scripts in the same folder unless you prefix everything with the package name (e.g., package.func). This isn’t practical when dealing with large or third-party codebases.

Ideally, I want MATLAB to:

• Let scripts call other scripts/functions located in the same folder without changing the current working directory, and
• Avoid name conflicts across projects,
• Without needing to rewrite existing code to add namespace prefixes everywhere.

This seems to be what toolboxes do.

How do people typically manage this in MATLAB? Is there a clean way to build a reusable code library from multiple projects without duplicating code or modifying everything to use package prefixes?