In-chat errors and automatic token refresh

This release displays Elements errors directly in the chat interface and adds automatic session token refresh before chat requests.

Features

• Show Elements errors inside the chat #1633  - Elements errors now appear directly in the chat conversation for easier debugging. (Author: @chase-crumbaugh )
• Auto-refresh expired session tokens #1615  - Added JWT expiry detection with a 30-second buffer, deduplicates concurrent refresh calls via fetchQuery, and falls back to the stale token on failure. Refresh is automatic for non-static sessions and skipped during replays. (Author: @walker-tx )