../../platform-assets/AppIcon.icon — source of truth for the Apple platform icon: an Apple Icon Composer bundle (layered artwork + gradient background), shared by Electron and iOS.
Assets.car + icon.icns — compiled from AppIcon.icon by actool (checked in so builds don't require Xcode 26+). Assets.car gives the native dynamic icon on macOS 26+ (liquid glass, light/dark/tinted); icon.icns is the static fallback used by older macOS and as electron-builder's mac.icon. The build/afterPack.js hook copies Assets.car into the app bundle, and CFBundleIconName=AppIcon (in mac.extendInfo) tells macOS to look for it. electron-builder has no native .icon support yet — see https://github.com/electron-userland/electron-builder/issues/9254.
icon.ico / icon.png — Windows / Linux icons.

Regenerating after editing AppIcon.icon

Requires Xcode 26+ (Icon Composer .icon support in actool):

cd web/electron/icons
TMP=$(mktemp -d)
DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer xcrun actool ../../platform-assets/AppIcon.icon \
  --compile "$TMP" --platform macosx --minimum-deployment-target 11.0 \
  --app-icon AppIcon --output-partial-info-plist "$TMP/partial.plist"
cp "$TMP/Assets.car" Assets.car
cp "$TMP/AppIcon.icns" icon.icns
rm -rf "$TMP"