Use .gitattributes to control Composer package exports

[Neluxx]

Add support for Git’s .gitattributes export-ignore directive to control which files are included when the package is distributed via Composer.

This allows us to exclude repository-only files (e.g. tests, CI configs, docs, tooling) from distribution archives and keep the package leaner.

Tasks

• Review the repository structure and identify files/directories to exclude.
• Add or update .gitattributes with export-ignore rules.
• Verify that Composer package archives contain only the required runtime files.

References

• https://git-scm.com/docs/gitattributes#_export_ignore
• https://madewithlove.com/blog/gitattributes/
• https://php.watch/articles/composer-gitattributes#export-ignore
• https://hannesvdvreken.com/2015/01/14/gitattributes/
• https://medium.com/@pavlakis/sharing-with-composer-and-gitattributes-4423f5c4967f