next.js

3b3df0ec - Harden the dev route matchers against reload races

Harden the dev route matchers against reload races Three independent fixes for the development route matcher manager: - A failed reload left waitTillReady holding a rejected promise, so one transient filesystem error while scanning failed every subsequent request until the next reload replaced it. The promise is now cleared when it rejects. - Concurrent reloads ran unserialized, interleaving scans of different filesystem states and mutating shared matcher objects. Reloads are now coalesced into one running and one queued scan; a caller that arrives mid-scan waits for the queued one, since the running scan may predate the change the caller wants to observe. - A route deleted after the matchers last scanned the filesystem could still match, and the ensure step then failed the request with a 500 where rendering the 404 page is expected. A PageNotFoundError from ensure now means the match is stale and is skipped.