fix(mac): wire CFBundleIconName so app icon renders in Finder and Sparkle dialog

Assets.xcassets/AppIcon.appiconset was complete and ASSETCATALOG_COMPILER_APPICON_NAME was set,
but without CFBundleIconName in Info.plist, Launch Services could not resolve the compiled
iconset in Assets.car. Both Finder and Sparkle's updater (NSApp.applicationIconImage) showed blank.

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

Author: finch-xu

agent-mac/RttysAgent/Info.plist

@@ -2,6 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>CFBundleIconName</key>
+	<string>AppIcon</string>
 	<key>LSUIElement</key>
 	<true/>
 	<key>SUFeedURL</key>