feat: Enhance server validation in server.js and improve gateway management in ServerManager and FilterManager, ensuring proper gateway configuration for jumphost and exit server types.

backend/server.js

@@ -306,6 +306,22 @@ const serversRoutes = createJsonDataRoutes('servers.json', (server, i) => {
     return `Server at index ${i} has invalid type (allowed: ${SERVER_TYPES.join(', ')})`;
   }
 
+  if (normalizedType === 'jumphost' || normalizedType === 'exit') {
+    if (!Array.isArray(server.gateways) || server.gateways.length === 0) {
+      return `Server at index ${i} must have gateways for type ${normalizedType}`;
+    }
+    const primaries = server.gateways.filter(g => g && g.primary);
+    if (primaries.length !== 1) {
+      return `Server at index ${i} must have exactly one primary gateway`;
+    }
+    for (let j = 0; j < server.gateways.length; j++) {
+      const gw = server.gateways[j] || {};
+      if (!gw.name || String(gw.name).trim().length === 0) {
+        return `Server at index ${i} gateway at index ${j} is missing name`;
+      }
+    }
+  }
+
   // Нормализуем тип, чтобы в S3 всегда лежали одинаковые значения
   server.type = normalizedType;
   return null;