Docs: CI badge uses the deprecated workflow-name URL and does not render

[beyondnetPeru]

README.md renders the build badge with the legacy name-based form:

https://github.com/beyondnetcode/Shell.Aop/workflows/CI%20/%20CD/badge.svg

The workflow is named CI / CD, and the embedded slash makes that URL ambiguous. Use the file-based form instead:

https://github.com/beyondnetcode/Shell.Aop/actions/workflows/build.yml/badge.svg

Acceptance criteria

• The badge renders a real status (not "no status") on the repo homepage.
• Same fix applied to README.en.md and README.es.md if they carry the badge.

Where

README.md, README.en.md, README.es.md.