v2.0.0

BREAKING

• Replaced endUserId option with rich user object (id, firstName, lastName, email, photoURL, plus arbitrary fields)
• Removed data-end-user-id and data-api-url script tag attributes from CDN auto-init
• Renamed apiUrl option to _embedUrl (internal/private)

Added

• user option for passing user identity (id, name, email, photo, custom fields)
• context option for page metadata and tags
• setUser() method for updating user identity after initialization (e.g., post-login)
• Auto-collection of page.url, page.referrer, page.title into context
• Handle chatsy:close postMessage from embed (allows embed to request widget close)
• API_URL constant extracted as single source of truth

Changed

• chatsy:init payload now sends user and context instead of endUserId
• Origin validation and iframe URL use API_URL constant with _embedUrl override
• README updated with new user/context configuration and setUser() documentation