fix(packaging): set Linux deb maintainer

electron-builder's fpm target requires a maintainer (or a package.json
author with an email) to produce a .deb. Add it under linux.maintainer
so the release build doesn't fail on the deb step.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: SDSLeon

electron-builder.yml

@@ -147,6 +147,7 @@ linux:
         - x64
   icon: build/icon.png
   category: Development
+  maintainer: SDSLeon <SDSLeon999@gmail.com>
   artifactName: ${productName}-${version}-${arch}.${ext}
 
 mac: