Add minimax.io provider

[bebecool]

Hello, could you please add MiniMax as a native provider in Blinko?

At the moment, MiniMax does not seem to work properly when configured through the OpenAI-compatible provider or through the Personal provider. The integration either fails or is not recognized correctly, which makes MiniMax unusable in practice inside Blinko.

It would be very helpful to have official MiniMax provider support with the proper base URL and model handling, instead of relying on OpenAI or Personal as a workaround.

Thanks