Rsync Manager — App Store release assets

Included:
- RsyncManager-AppIcon-1024.png — 1024×1024 marketing icon master, opaque PNG.
- Xcode Assets.xcassets/AppIcon.appiconset — all required macOS icon raster sizes.
- AccentColor.colorset — native system accent used throughout the UI.

Before App Store submission:
- Set your Apple Development/Distribution team in Xcode Signing & Capabilities.
- Review the bundle identifier and version/build number.
- Archive with the Release scheme and validate the archive in Xcode Organizer.
- Capture App Store screenshots from the final signed build on your target macOS version.
