Fix shutdown blocking and startup order in dev-electron script

- Use .unref() on the SIGKILL grace period timer so shutdown exits
  immediately instead of unconditionally blocking for 1.2 seconds
- Move cleanupStaleDevApps() before startWatchers() to ensure stale
  processes are cleaned up before any new activity begins

Co-authored-by: Julius Marminge <juliusmarminge@users.noreply.github.com>

Author: cursoragent

apps/desktop/scripts/dev-electron.mjs

@@ -184,16 +184,13 @@ async function shutdown(exitCode) {
 
   await stopApp();
   killChildTree("TERM");
-  await new Promise((resolve) => {
-    setTimeout(resolve, childTreeGracePeriodMs);
-  });
-  killChildTree("KILL");
+  setTimeout(() => killChildTree("KILL"), childTreeGracePeriodMs).unref();
 
   process.exit(exitCode);
 }
 
-startWatchers();
 cleanupStaleDevApps();
+startWatchers();
 startApp();
 
 process.once("SIGINT", () => {