component.js now creates an AbortController for each page mount, passing
it to load(). On unmount, the controller is aborted to cancel in-flight
requests that would otherwise mutate unmounted state.
Page load functions consistently pass the signal to apiFetch and guard
state mutations with abort checks. This eliminates the need for per-page
abortController boilerplate and prevents stale errors from appearing on
rapid navigation.
Users page now guards catch block and loading state cleanup against
aborted requests, matching passkeys.js pattern.
mteehan
ca27ea5522