macos: declare CFBundleLocalizations so UI culture is detected in .app

Without a CFBundleLocalizations array, macOS reports "en" to
CFBundleCopyPreferredLocalizations regardless of the user's language
preferences, so CultureInfo.CurrentUICulture always resolved to English
inside the packaged .app. Declare the languages we actually ship (en,
zh-Hans) so the system returns the correct match.

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

Author: mahoshojoHCG

WinPartFlash.Gui/MacOS/Info.plist.template

@@ -4,6 +4,11 @@
 <dict>
     <key>CFBundleDevelopmentRegion</key>
     <string>en</string>
+    <key>CFBundleLocalizations</key>
+    <array>
+        <string>en</string>
+        <string>zh-Hans</string>
+    </array>
     <key>CFBundleDisplayName</key>
     <string>WinPartFlash</string>
     <key>CFBundleName</key>