steel-browser 是做什麼的？
Use this skill for any web task where WebFetch or curl would fail or be insufficient — pages that require JavaScript to render, forms to fill and submit, screenshots or PDFs of live pages, CAPTCHA/bot-protection bypass, login flows, and multi-step browser navigation with persistent session state. WebFetch returns empty HTML for JS-rendered pages; this skill runs a real cloud browser that executes JavaScript, maintains cookies, clicks buttons, and handles anti-bot measures. Trigger when the user wants you to actually perform a web task (visit, interact, extract, capture) rather than just write code for it. Skip only for: static pages a simple GET can fetch, localhost or private-network targets, writing browser automation code the user will run themselves, or conceptual questions about browser tools.