chore: source app display name from platform config

linux/CMakeLists.txt

@@ -8,6 +8,10 @@ set(BINARY_NAME "mobile")
 # The unique GTK application identifier for this application. See:
 # https://wiki.gnome.org/HowDoI/ChooseApplicationID
 set(APPLICATION_ID "cn.saltworks.kirimemo.mobile")
+# Human-readable application name, shown in the window title bar.
+# Keep it in sync with the Android `app_name` string resource and the
+# `CFBundleDisplayName` / `CFBundleName` entries in ios/Runner/Info.plist.
+set(APPLICATION_TITLE "KiriMemo")
 
 # Explicitly opt in to modern CMake behaviors to avoid warnings with recent
 # versions of CMake.