Work around account switching failing to open the CEF debugger socket (#668)

* Work around account switching failing to open the CEF debugger socket

this automates lsof and gdb to force close the socket before steam finishes shutting down (from RegisterForShutdownStart)

* lint

* fix LD_LIBRARY_PATH for gdb

frontend/src/steamfixes/socket.ts

@@ -0,0 +1,16 @@
+import Logger from '../logger';
+
+const logger = new Logger('CEFSocketFix');
+
+const closeCEFSocket = DeckyBackend.callable<[], void>('utilities/close_cef_socket');
+
+export default function cefSocketFix() {
+  const reg = window.SteamClient?.User?.RegisterForShutdownStart(async () => {
+    logger.log('Closing CEF socket before shutdown');
+    await closeCEFSocket();
+  });
+
+  if (reg) logger.debug('CEF shutdown handler ready');
+
+  return () => reg?.unregister();
+}