feat(MikrotikConnection): add MikroTik connection testing functionality in ServerModal; update API routes and README for new encryption key and connection endpoint

frontend/src/components/server/ServerModal.jsx

@@ -1,5 +1,6 @@
 import { useState, useEffect, useRef } from 'react';
-import { IconPlus, IconEdit, IconTrash, IconServer, IconWorld, IconMapPin } from '@tabler/icons-react';
+import { IconPlus, IconEdit, IconTrash, IconServer, IconWorld, IconMapPin, IconRouter, IconPlug } from '@tabler/icons-react';
+import api from '../../lib/api.js';
 import { 
   makeGateway, 
   normalizeGateways, 
@@ -76,6 +77,8 @@ function ServerModal({ show, mode = 'add', server, onSave, onClose, error: exter
   const [localServer, setLocalServer] = useState(getEmptyServer());
   const [customProvider, setCustomProvider] = useState('');
   const [internalError, setInternalError] = useState('');
+  const [mikrotikTesting, setMikrotikTesting] = useState(false);
+  const [mikrotikTestResult, setMikrotikTestResult] = useState(null);
 
   const isEditMode = mode === 'edit';
   const error = externalError || internalError;
@@ -119,6 +122,7 @@ function ServerModal({ show, mode = 'add', server, onSave, onClose, error: exter
     }
     if (!show) {
       initializedRef.current = false;
+      setMikrotikTestResult(null);
     }
   }, [show, server, isEditMode]);
 
@@ -560,6 +564,103 @@ function ServerModal({ show, mode = 'add', server, onSave, onClose, error: exter
                   </div>
                 </div>
               )}
+
+              {/* MikroTik — только для jumphost */}
+              {localServer.type === 'jumphost' && (
+                <div className="mt-4 pt-3 border-top">
+                  <label className="form-label d-flex align-items-center gap-2">
+                    <IconRouter size={18} />
+                    MikroTik RouterOS API
+                  </label>
+                  <div className="row g-3">
+                    <div className="col-md-4">
+                      <label className="form-label small">Хост</label>
+                      <input
+                        type="text"
+                        className="form-control form-control-sm"
+                        value={localServer.mikrotikHost || ''}
+                        onChange={(e) => handleFieldChange('mikrotikHost', e.target.value)}
+                        placeholder={localServer.ip || 'IP или DNS'}
+                      />
+                    </div>
+                    <div className="col-md-2">
+                      <label className="form-label small">Порт</label>
+                      <input
+                        type="number"
+                        className="form-control form-control-sm"
+                        value={localServer.mikrotikPort || '8728'}
+                        onChange={(e) => handleFieldChange('mikrotikPort', e.target.value)}
+                        placeholder="8728"
+                      />
+                    </div>
+                    <div className="col-md-3">
+                      <label className="form-label small">Пользователь</label>
+                      <input
+                        type="text"
+                        className="form-control form-control-sm"
+                        value={localServer.mikrotikUser || 'admin'}
+                        onChange={(e) => handleFieldChange('mikrotikUser', e.target.value)}
+                        placeholder="admin"
+                      />
+                    </div>
+                    <div className="col-md-3">
+                      <label className="form-label small">Пароль</label>
+                      <input
+                        type="password"
+                        className="form-control form-control-sm"
+                        value={localServer.mikrotikPassword ?? ''}
+                        onChange={(e) => handleFieldChange('mikrotikPassword', e.target.value)}
+                        placeholder={localServer.hasMikrotikPassword ? '••••••' : 'Введите пароль'}
+                      />
+                    </div>
+                  </div>
+                  <div className="mt-2 d-flex align-items-center gap-2">
+                    <button
+                      type="button"
+                      className="btn btn-outline-primary btn-sm d-flex align-items-center gap-1"
+                      disabled={mikrotikTesting || !(localServer.mikrotikHost || localServer.ip)}
+                      onClick={async () => {
+                        setMikrotikTestResult(null);
+                        setMikrotikTesting(true);
+                        try {
+                          const hasPassword = localServer.mikrotikPassword && String(localServer.mikrotikPassword).trim() !== '';
+                          const payload = hasPassword
+                            ? {
+                                host: localServer.mikrotikHost || localServer.ip,
+                                port: localServer.mikrotikPort || 8728,
+                                user: localServer.mikrotikUser || 'admin',
+                                password: localServer.mikrotikPassword,
+                              }
+                            : (localServer.hasMikrotikPassword && (localServer.id || localServer.dns || localServer.ip))
+                              ? { serverId: localServer.id || localServer.dns || localServer.ip }
+                              : null;
+                          if (!payload) {
+                            setMikrotikTestResult({ ok: false, message: 'Введите пароль или сохраните сервер с паролем' });
+                            return;
+                          }
+                          const { data } = await api.post('/mikrotik/test-connection', payload);
+                          setMikrotikTestResult(data);
+                        } catch (err) {
+                          setMikrotikTestResult({
+                            ok: false,
+                            message: err.response?.data?.message || err.message || 'Ошибка соединения',
+                          });
+                        } finally {
+                          setMikrotikTesting(false);
+                        }
+                      }}
+                    >
+                      <IconPlug size={14} />
+                      {mikrotikTesting ? 'Проверка...' : 'Проверить соединение'}
+                    </button>
+                    {mikrotikTestResult && (
+                      <span className={mikrotikTestResult.ok ? 'text-success' : 'text-danger'}>
+                        {mikrotikTestResult.ok ? '✓ ' + (mikrotikTestResult.message || 'OK') : '✗ ' + mikrotikTestResult.message}
+                      </span>
+                    )}
+                  </div>
+                </div>
+              )}
             </div>
 
             <div className="modal-footer">