Cache the PS5 system language once per process and share the resolved locale across Toolbox, plain notifications, and rich notifications. Keep ShellUI queries behind the registered trampoline, localize the daemon welcome toast, and cover cache refresh and localized payload generation in host tests.
Place the welcome title in subMessage and the build version with author in message to match the PS5 toast layout. Shorten dirty build labels to dirty-SHA.
Generate shared version metadata from an exact Git tag, falling back to dirty-YYMMDD-SHA for untagged or modified trees. Show the version and author in the startup toast and reuse the generated version across ShellUI.