InfiniteScroll

Sentinel-driven lazy pagination — server appends HTML + a next-cursor header.

Note
infinitescroll.Render(cfg) observes a sentinel and GETs cfg.RPCPath?cursor=X; the handler returns the next page's HTML and sets X-Gofastr-Infinite-Cursor (empty = end). Needs a per-page RPC, so it's shown as a note here.