Two independent ways a restart leaves the SPA unable to navigate, both of
which look identical to a user - a click that does nothing.
1. The router awaits loadEnabledPlugins() to gate plugin routes. An app-pool
restart leaves that request hanging (IIS queues it while the worker starts)
and axios sets no timeout, so the navigation never resolves. Worse, the
promise is cached, so every later navigation awaited the same dead request
and stayed frozen long after the backend recovered. Bound the wait and fail
open on expiry, and drop the cached promise when an attempt times out or
fails so the next navigation retries. The setup-state probe in the guard
gets the same bound (it already fails open, defaulting to "complete").
2. A deploy replaces the content-hashed chunk files, so a tab open across it
asks for chunks that no longer exist and the dynamic import rejects with
nothing handling it. Reload once on a chunk-load error, via router.onError
and Vite's preloadError, guarded by a sessionStorage flag against a reload
loop and cleared on the next successful navigation.
Also stop index.html being cached: it names the hashed chunks, so a stale copy
points at files the deploy already deleted. It now revalidates while the
hashed assets under assets/ cache for a year.
a7fe2c8353