feat: Improve gateway handling in ServerManager by ensuring safe access to gateways array and enhancing the addition of new gateways, promoting better server configuration reliability.

frontend/src/ServerManager.jsx

@@ -1095,7 +1095,7 @@ function ServerManager() {
           <>
             <div className="form-label">Шлюзы</div>
             <div className="list-group list-group-flush border rounded mb-2">
-              {newServer.gateways.map((gw, idx) => (
+              {(newServer.gateways || []).map((gw, idx) => (
                 <div key={gw.id || idx} className="list-group-item">
                   <div className="row g-2 align-items-end">
                     <div className="col-12 col-md-4">
@@ -1177,7 +1177,12 @@ function ServerManager() {
             <button
               type="button"
               className="btn btn-outline-primary btn-sm"
-              onClick={() => setNewServer({ ...newServer, gateways: [...newServer.gateways, makeGateway({ primary: newServer.gateways.length === 0 })] })}
+              onClick={() => {
+                setNewServer((prev) => {
+                  const list = Array.isArray(prev.gateways) ? prev.gateways : [];
+                  return { ...prev, gateways: [...list, makeGateway({ primary: list.length === 0 })] };
+                });
+              }}
             >
               <IconPlus className="icon" />
               Добавить шлюз
@@ -1629,8 +1634,9 @@ function EditServerModal({ show, server, onChange, onSave, onClose }) {
                     type="button"
                     className="btn btn-outline-primary btn-sm"
                     onClick={() => {
-                      const list = [...(localServer.gateways || []), makeGateway({ primary: !(localServer.gateways || []).length })];
+                      const list = Array.isArray(localServer.gateways) ? localServer.gateways : [];
-                      const next = { ...localServer, gateways: list };
+                      const nextList = [...list, makeGateway({ primary: list.length === 0 })];
+                      const next = { ...localServer, gateways: nextList };
                       setLocalServer(next);
                       onChange && onChange(next);
                     }}