Board — compositional kanban / sortable-list primitive · UIPKGE

Six small composable components for any board / kanban / sortable-list surface — opinionated about drop targeting and animation, agnostic about layout, data, and chrome. Drop `<Board>` around a grid of `<BoardLane>` columns; nest `<BoardLaneHeader>`, `<BoardLaneBody>`, `<BoardLaneEmpty>`, and `<BoardCard>` items inside each lane. State lives in a sibling `useBoard()` hook (insertion-index drop math, keyboard a11y, accept predicate). Cards use native HTML5 drag-and-drop (draggable + onDragStart / onLaneDragOver / onLaneDrop) — the lane components emit drag events up to the consumer, which threads them through useBoard and feeds the resulting state back in as props. Three-level React context (board → lane → card) mirrors the Timeline / Card sub-component pattern.