Rename `router.py` to `routes.py` for better clarity

[degisew]

Hi,

I’ve been exploring your project structure and really appreciate how you’ve applied Domain-Driven Design (DDD) principles — it's well-organized! However, I wanted to suggest a small change regarding the naming of the router.py file.

Since we typically define multiple routes, I think routes.py would be a more descriptive and clearer name. It's similar to how we use urls.py in Django, which helps in maintaining clarity across the project.

What are your thoughts on this?

Thanks!