dove-a/dsh-chat-window-fold

Fold and expand the dsh web chat window automatically: event-cycle checkpoints (every 25 session events, from N=75) fold older loaded pages beyond the recent 50 rows when the viewport sits at the bottom; scrolling to the very top appends up to 50 earlier messages with the viewport kept in place, repeated until no more history. Per-session isolated; window stays below ~75 rows (low-end friendly); system "Load earlier" button hidden; configurable via row config (foldThreshold=50, foldCheckEvery=25). A DSH web profile bundle.