automate consistency checks

when we add or archive a component, we often forget one of the following:
- repo's default.xml
- README.md
- aggregator build
- dist tool https://ci-maven.apache.org/job/Maven/job/maven-box/job/maven-dist-tool/job/master/site/index.html
- sources list https://maven.apache.org/scm.html

Review the repo's default.xml, README.md, aggregator build, dist tool, and sources list first. Trace how component additions and archivals affect each location and identify the existing build entry points for consistency checks. Done means these locations are checked automatically when components change.

Written by the indexing model from the issue text.