Say once, the first time, that closing the window keeps the launcher in the tray (#376)

The close button parks the launcher in the tray by design, but to
someone who doesn't know that, a window that vanishes with nothing to
show for it looks hung, and the reports end with killing the process
(#45, #215).

The first time the window closes to the tray, a system notification
says the launcher is still running, that it's in the tray, and that
Settings can turn this off. `LauncherUi::hidden_to_tray` sends it
through the host and records it in `Settings::tray_hint_shown`, so it
happens once per install. The desktop shell calls it from the
close-request path only, for both ways of going to the tray; a window
hidden from the tray icon, or started hidden at login, gets no hint.

Two strings, with rows in all ten complete catalogs. A UI test checks
the hint is sent once and recorded.

Co-authored-by: YangXZ2008 <141027290+YangXZ2008@users.noreply.github.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

apps/artcraft-launcher/src/main.rs

@@ -790,10 +790,14 @@ impl eframe::App for Shell<'_> {
         if ctx.input(|i| i.viewport().close_requested()) && !self.quitting && !self.launcher.closed_to_tray {
             match on_close(self.launcher.tray.is_some(), self.launcher.ui.settings.close_to_tray, self.window_hides) {
                 OnClose::Hide => {
+                    self.launcher.ui.hidden_to_tray(&mut self.launcher.host);
                     ctx.send_viewport_cmd(egui::ViewportCommand::CancelClose);
                     self.put_away(ctx);
                 }
-                OnClose::ToTray => self.launcher.closed_to_tray = true,
+                OnClose::ToTray => {
+                    self.launcher.ui.hidden_to_tray(&mut self.launcher.host);
+                    self.launcher.closed_to_tray = true;
+                }
                 OnClose::Quit => {}
             }
         }