feat(ipsec): add certificate export functionality by name

- Implemented a new backend route for exporting existing client certificates in .p12 format by name.
- Enhanced the frontend to support exporting certificates directly from the IPsec server grid.
- Updated the IPsec page to manage certificate states and handle exports effectively.
- Introduced new utility functions for certificate handling and improved data structures to accommodate the changes.
- Added tests to ensure the reliability of the new certificate export feature.

backend/src/services/ipsec-ca.ts

@@ -107,15 +107,24 @@ export async function issueClientCertificate(
   return { certName, commonName: args.userName.trim(), existed: false }
 }
 
+/** Экспорт произвольного сертификата по имени (существующие client1/anakondra и т.п.). */
+export async function exportCertificateP12ByName(
+  client: MikrotikClient,
+  certName: string,
+  passphrase: string,
+): Promise<{ fileName: string; content: Buffer; certName: string }> {
+  const name = certName.trim()
+  const cert = await findCertificate(client, name)
+  if (!cert) throw new Error(`Сертификат ${name} не найден на роутере`)
+  const { fileName, content } = await client.exportCertificatePkcs12({ name, passphrase })
+  return { fileName, content, certName: name }
+}
+
 /** Экспорт клиентского .p12 (сертификат + ключ; CA в цепочке) с роутера. */
 export async function exportClientP12(
   client: MikrotikClient,
   userName: string,
   passphrase: string,
 ): Promise<{ fileName: string; content: Buffer; certName: string }> {
-  const certName = clientCertName(userName)
-  const cert = await findCertificate(client, certName)
-  if (!cert) throw new Error(`Сертификат ${certName} не найден на роутере`)
-  const { fileName, content } = await client.exportCertificatePkcs12({ name: certName, passphrase })
-  return { fileName, content, certName }
+  return exportCertificateP12ByName(client, clientCertName(userName), passphrase)
 }