fix: botched edit

backend/chat/src/main.go

@@ -1067,6 +1067,14 @@ func handleAdminRestart(w http.ResponseWriter, r *http.Request) {
 
 func handleAdminSystemSummary(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	summary := getAdminSystemSummary()
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(summary)
+}
 
 func handleAdminUsers(w http.ResponseWriter, r *http.Request) {
 	switch r.Method {