Introduce Beyond Compare Windows package metadata and scripts for
winget. Adds input manifest
(ee/maintained-apps/inputs/winget/beyond-compare.json) plus install and
uninstall PowerShell scripts that handle Inno Setup silent install flags
and registry-based uninstaller discovery. Updates outputs: registers the
app in ee/maintained-apps/outputs/apps.json and adds a versioned output
file with installer URL, sha256, and script refs
(ee/maintained-apps/outputs/beyond-compare/windows.json).
