Kanban: a shared CRDT document

One live.doc, zero RPC handlers. A cards map plus one order array per column; every edit applies to the local replica in the same tick and merges everywhere. Cards move between columns with their arrow buttons. Concurrent moves from two tabs both survive (per-element CRDT identity), and offline edits reconcile in one exchange on reconnect - the local replica IS the offline queue.

Editing as Funky Donut (3d0105a9) - cards carry their creator's color; a ring marks a peer's fresh edit