fix: disable HTTP keep-alive and update nginx proxy config

- Set http1_keep_alive(false) on hyper server to prevent connection
  reuse issues with nginx reverse proxy
- Clean up nginx proxy config: remove upstream block, use direct
  proxy_pass to 127.0.0.1:5678
- Update AppLauncherOverlay and appLauncher store with UI fixes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/archipelago/src/server.rs

@@ -163,6 +163,7 @@ impl Server {
                 });
 
                 if let Err(e) = Http::new()
+                    .http1_keep_alive(false)
                     .serve_connection(stream, service)
                     .with_upgrades()
                     .await