fix(dev): allow Ctrl+C to promptly kill dev server by closing active connections (#13020)

* fix(dev): allow Ctrl+C to promptly kill dev server by closing active connections and adding force-exit timeout

* test(dev): add regression assertions for prompt dev server exit on Ctrl+C

* docs(changelog): add fragment for #13020

scripts/dev/run-next.mjs

@@ -235,15 +235,31 @@ async function start() {
     process.exit(1);
   });
 
+  let isShuttingDown = false;
   const shutdown = async (signal) => {
+    if (isShuttingDown) {
+      // Second Ctrl+C / signal forces immediate exit
+      process.exit(1);
+    }
+    isShuttingDown = true;
+
+    // Safety net: force exit after 2s if keep-alive sockets or Next.js app close hangs
+    const forceExitTimer = setTimeout(() => {
+      process.exit(0);
+    }, 2000);
+    forceExitTimer.unref?.();
+
     systemdNotifier.stopping();
     try {
+      server.closeIdleConnections?.();
+      server.closeAllConnections?.();
       await new Promise((resolve) => server.close(resolve));
       await globalThis.__omnirouteRequestShutdown?.(signal);
       await nextApp.close();
     } catch (error) {
       console.error("[SHUTDOWN] Failed during signal:", signal, error);
     } finally {
+      clearTimeout(forceExitTimer);
       process.exit(0);
     }
   };