django/django-localflavor ? reverse-engineered prompt

Build me a small Django library that adds country specific form helpers for things like postal codes, national ID numbers, and other local validation rules.

I want it to feel like the old contrib localflavor tools, so apps can just import a field or validator and use it in forms and models without writing custom regexes everywhere. Please include a few examples for different countries, solid validation messages, and clear documentation so people know which fields are available and how to use them. Add tests for the main behaviors and make sure the package is set up like a real open source project, with good docs and release ready structure.

If you need to check the latest Django patterns or packaging docs, look them up online first.