Major.Minor Document Versioning

Until now, every document version was a major version. Publish a new version, everyone has to sign again. Even for a typo fix.

Documents now support major and minor versions. Publish a minor version and existing signatures stay valid. No re-signing needed. Save that for when the content actually changes in a meaningful way.

Major versions still work the same. Bump the major number and everyone goes through the approval and signature flow again. You decide which one fits.