dont require LLMClient to use stagehand

[seanmcguire12]

related: #368

why

• we want users to be able to use non-ai features of stagehand without requiring them to set up an LLM client

what changed

• only use default LLM client if they have an API key, otherwise dont pass in an LLM client & only error if they try to use AI features

test plan

• e2e tests, evals

[changeset-bot]

🦋 Changeset detected

Latest commit: 02f8bb2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@browserbasehq/stagehand	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[kamath]

don't think existing evals are going to be enough here; can we add a simple eval in combination that tries to use stagehand without any LLM key?

[kamath]

good stuff. i like that we now remove LLM API keys from e2e altogether to test this :)