svelte-async-revert-repro

Minimal reproduction for the "DOM reverts to pre-navigation render" bug in Svelte 5 async mode + SvelteKit. See ISSUE.md for the full write-up to paste into a GitHub issue.

Run

npm ci
npm run dev          # opens on :5173 by default

Open http://localhost:5173/fundraisers/1 and click "Mark reviewed and go to next".

Expected: label becomes LABEL for id=2. Actual: label briefly shows LABEL for id=2 (~5 ms), then reverts to LABEL for id=1 and stays there. The URL is /fundraisers/2 and reactive state has the new value, but the DOM doesn't.

Automated check (optional)

Start the dev server on port 5200 (npm run dev -- --port 5200), then in another terminal:

npm i -D playwright
node verify.mjs

It samples .label every 50 ms for 3 s and exits 1 if the value is stuck.