request
Asks the browser to keep this origin's storage, and reports whether it now will.
Without it the queue lives in best-effort storage, which a browser is free to evict when the device runs low on space — pending jobs would disappear without a trace. With it the queue survives until the user clears the site's data.
Call it at a moment that makes sense for the app rather than on every start: Firefox asks the user for permission, while Chromium and Safari decide silently from how engaged the user is. The request is skipped when the browser already granted persistence, so calling it twice costs nothing.
Returns false where the Storage API is missing, which is the same as saying "the queue may be evicted", never that something went wrong.