Don't require an assistant to use a model

[242816]

Currently we have to create an assistant so users can use a model.

Allow the model to be selected from the console.

• [ ] Replace AI assistant with model selector.
• [ ] AI Assistant can have none selected
• [ ] send_message.rs takes a model_id which will override the model id in the prompt.

Other Ideas

• Remove prompt completely from console
• Have list of assistant
• Click assistant and then get a prompt.
• What does chat gpt do?

Console send a model_id or a prompt_id

• [ ] If prompt_id in url then do that
• [ ] else show a model selector
• [ ] screen chnages if it is an assistant.
• [ ] conversations.rs make prompt optinal
• [ ] send_message.rs needs model_id
• [ ] separate URL for assistants

Step by Step

• [ ] Click on assistant, takes you to console with that assistant pre-selected.
• [ ] Need new url (or a param)
• [ ] select assistant.