Add keyboard-interactive (2FA/MFA) authentication support

[Copilot]

Adds support for SSH servers requiring keyboard-interactive authentication (2FA/MFA). Previously, connecting to hosts with multi-factor auth would fail silently.

Changes

Frontend

• New KeyboardInteractiveModal component displays server prompts and collects user responses
• Integrated at app level to handle prompts from SSH, SFTP, and port forwarding connections
• Added EN/CN translations for modal UI

Backend

• keyboardInteractiveHandler.cjs - Shared module for centralized request/response management across all connection types
• SSH, SFTP, and port forwarding bridges now handle the keyboard-interactive event from ssh2
• Connection timeout increased to 120s to allow time for 2FA input
• IPC bridge extended with onKeyboardInteractive and respondKeyboardInteractive methods

Flow

Server → ssh2 keyboard-interactive event → Main process → IPC → Modal prompt
User input → IPC → Main process → ssh2 finish callback → Connection established

Notes

• Single IPC handler registration in SSH bridge serves all connection types via shared module
• Supports multiple sequential prompts (some servers ask multiple questions)
• Password fields masked based on prompt's echo property

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Feature]希望增加一个双因子2FA登录的方式</issue_title>
<issue_description>希望增加一个双因子登录2FA的方式，类似于如下功能：

不然的话有些节点无法登录上去，需要用其他软件替代</issue_description>

<agent_instructions>根据用户的截图，调研一下用户所提到的这个功能实现的可能性，如果可以，尝试实现一下。
注意：如果需要填写多因素认证的code，请考虑全局弹modal让用户填写，因为sftp 跳板机 端口转发功能可能都涉及到多因素认证，如果此功能是通用的，请封装统一的modal来实现。</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes [Feature]希望增加一个双因子2FA登录的方式 #83

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.