v0.21.7

Fixes

• The app can no longer reload itself in a loop when a route chunk is missing. If a reverse proxy caches the HTML shell, an upgrade leaves the browser asking for route files that no longer exist; the router reloads the document, receives the same stale shell and repeats forever — which looked like a page that refreshes on its own, and it fired even on hover because hovering prefetches a route chunk. The HTML document is now served with Cache-Control: no-store (hashed assets keep their year-long immutable caching, data requests and the event stream are untouched), and a small guard allows one automatic reload for a failed chunk, then replaces the app with a clear explanation and a manual reload button instead of looping again.