Allow using the current model as TASK_MODEL

[lksj92hs]

Describe your feature request

Currently the task model (the model used for summarization, web search, etc.) is fixed with the TASK_MODEL environment variable and can't be changed without restarting chat-ui. It would be useful if we can use the current model as TASK_MODEL because:

• If we are using a large model for the current chat, it makes sense to use a larger task model as well to improve the quality of the results even with the cost of a bit more time waiting for a response. On the other hand, if we are using a smaller model, we won't have to pay the price of using a big model as task model.
• For some chats the task model can be a privacy issue - e.g. if we are uploading sensitive documents, we may not want to use a public task model. Also there is a reasonable expectation by the user that his requests will be send only to the model we have explicitly selected with the current chat but they can be send to the task model as well without any indication or warning.

Implementation idea

Implement a special value for the TASK_MODEL (e.g. <current_model> or something like this) to use the current chat model as task model instead of using a concrete task model.

[nsarrazin]

Hi, I think that would be a good idea. Maybe it even make sense that if TASK_MODEL is '' or undefined we apply this behaviour? Currently it just takes the first model in the list which is pretty arbitrary.

[lksj92hs]

Yes, that would work fine too. Additional plus is that the user won't be surprised by chat-ui using another model "out of the blue" if she or he do not know what a task model is.