[FEATURE]: 添加切换提供商或者快速修改密钥的功能

[WqyJh]

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

1. 添加了xiaomi mimo的一个code plan的密钥，回车后能出现模型选择菜单；
2. 选择mimo v2.5 pro模型后，进行交互时报401 API错误；
3. 此时在对话交互窗口找不到能够切换提供商或者快速修改密钥的功能；
4. 希望类似kimi-code那样提供一个/provider的编辑功能，以便快捷地增删改提供商信息；

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Mirrored from XiaomiMiMo/MiMo-Code#254 — original author @Huaweidev.