Improve SSE status and event auth handling

go-server/internal/api/events.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"net/http"
+	"time"
 
 	"github.com/local-mcp/local-mcp-go/internal/events"
 )
@@ -24,6 +25,8 @@ func handleSSE(broker *events.Broker) http.HandlerFunc {
 		// Subscribe to event broker
 		ch := broker.Subscribe()
 		defer broker.Unsubscribe(ch)
+		heartbeat := time.NewTicker(15 * time.Second)
+		defer heartbeat.Stop()
 
 		// Send initial connection event
 		w.Write([]byte("data: {\"type\":\"connected\"}\n\n"))
@@ -38,6 +41,9 @@ func handleSSE(broker *events.Broker) http.HandlerFunc {
 				}
 				w.Write(msg)
 				flusher.Flush()
+			case <-heartbeat.C:
+				w.Write([]byte(": keepalive\n\n"))
+				flusher.Flush()
 			case <-r.Context().Done():
 				return // client disconnected
 			}