Add Support for o3-deep-research

There are 4 issues.

1) Today o3-deep-research is not an available model. I thus need to add it to my RECOMMENDED MODELS to bypass that check.

2) It requires the web_serach_preview tool be defined. So I need to define it in agent-loop.ts

3) I need to specify/hook into the tools; e.g. if the model is o3-deep-research, insert [websearchtool]

4) When calling the model it doesn't support "high" reasoning so I need to pass --reasoning medium

None of this is particularly difficult, but it'd be nice if this model were supported in CLI.