Add an option to disable delegation to browsing agent

[tobitege]

What problem or use case are you trying to solve?

Delegation to browsing agent is (almost) not stoppable, unless CTRL+C everything, it eats tokens like a mad cookie monster!
The agent spends thousands of tokens to even get over the cookie acceptance prompt of Google's landing page,
especially if its not in English.

Do you have thoughts on the technical implementation?

An option like for LLM class, usable via config.toml or env or docker....

Describe alternatives you've considered

Deleting the browsing_agent /sarcasm 😂