fix: raise the proxy and tunnel write timeout to 120s

graceful.WithDefaults applies a 10s write timeout, which cut any slower
response off mid-flight and left the client with an empty reply rather
than an error. The upstream is the developer's own application and may
legitimately take longer.

Closes #302

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JYzGVwAKQ4ormxRHZg1eDu

Author: alnr

cmd/cloudx/proxy/helpers.go

@@ -239,6 +239,11 @@ func runReverseProxy(ctx context.Context, h *client.CommandHelper, stdErr io.Wri
 	server := graceful.WithDefaults(&http.Server{
 		Addr:    addr,
 		Handler: ch.Handler(mw),
+		// graceful.WithDefaults would otherwise apply a 10s write timeout, which
+		// cuts any slower response off mid-flight and leaves the client with an
+		// empty reply. The upstream here is the developer's own application and
+		// may legitimately take longer than that.
+		WriteTimeout: 120 * time.Second,
 	})
 
 	if conf.isTunnel {