feat: SSH tunnel support

- Add ssh2 dependency for SSH port forwarding
- NewConnectionDialog: SSH toggle + host/port/user/password/privateKey/passphrase form
- connection.ts: createSshTunnel() with local port forwarding
- Connect ioredis through SSH tunnel when sshEnabled
- Clean up SSH client + tunnel server on disconnect
- i18n keys for all SSH fields (zh-CN + en)
- Add sshPassphrase to all ConnectionConfig types

src/i18n/locales/zh-CN.ts

@@ -31,6 +31,13 @@ export default {
     username: '用户名',
     tls: '启用 TLS',
     ssh: 'SSH 隧道',
+    sshHost: 'SSH 主机',
+    sshPort: 'SSH 端口',
+    sshUsername: 'SSH 用户名',
+    sshPassword: 'SSH 密码',
+    sshPrivateKey: '私钥路径',
+    sshPassphrase: '私钥密码',
+    selectFile: '选择文件',
     connect: '连接',
     disconnect: '断开',
     deleteConfirm: '删除此连接？',