Support more AI languages

By default the app uses Llama3.2:3b which lists the following:

Supported Languages: English, German, French, Italian, Portuguese, Hindi, Spanish, and Thai are officially supported. Llama 3.2 has been trained on a broader collection of languages than these 8 supported languages.

It should be relatively easy to instruct the AI to reply in any of those languages if the user wants it to.

For the time being the app would remain in English but at least the user should be able to choose a conversation language.