Add examples/integrations/ with tested examples for browser-use, Crawl4AI,
Scrapling, LangChain, Selenium, undetected-chromedriver, and agent-browser.
Add js/examples/stagehand.ts for Stagehand (TypeScript).
README: new "Framework Integrations" subsection with two integration
patterns (direct binary launch vs CDP connect) and table linking all 8 examples.
