Live in-progress drawing on the whiteboard. A shape being drawn is now relayed while the pointer is still down, so peers watch it grow instead of seeing it pop in whole on release. The draft rides the existing volatile presence channel (/presence, type:"draft") — never persisted, never merged into the CRDT, never published to NATS — and the real add op on pointer-up stays the only commit; peers drop the draft the moment the committed shape with that id arrives, with a 5 s TTL backstop and an explicit end for degenerate draws that commit nothing. Each frame carries the whole shape (not a delta), so a dropped frame is healed by the next one and the channel needs no sequencing or acks; it is throttled at 80 ms leading+trailing through the shared /static/throttle.js. The pattern is documented as reusable in docs/async-layers.md ("commit on release, relay while moving") and covered by a red-proofed two-context Playwright test.