A catalog of 500 products, paginated. Every visible row mounts its own qr-tag Svelte island — up to 25 per page — whose QR encodes the product code, title, unit price, the amount you type, and the line total. The amount box is LiveView-owned: each edit round-trips to the server, which recomputes the total and pushes fresh props back to that one island (which re-encodes). Paging tears down this page's islands and mounts the next — mount/teardown churn on top of the per-row prop-sync.

Flip Eager mount to compare cold-load behavior: on, the QR islands are mounted by mountStatic() the instant app.js parses — before the socket connects — so they paint immediately; off, each waits for the KeenApp hook after connect. The toggle reloads the page, since eager only applies to the initial paint (the qty inputs are LiveView-owned and stay interactive only after connect either way).