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.
Aligns user and permissions storage with the existing sessionStorage-based
token model. Eliminates the dual-write pattern and stale cross-session data.
mteehan