The host's access function is memoized on `initialState` and runs
exactly once per commit. Plugins that maintain identity-scoped
caches the access predicate reads from (e.g. an org context cache)
had no way to seed those caches synchronously before the caller's
`setInitialState({currentUser: ...})` fired — any post-commit hydrate
couldn't widen the predicate, leaving the sidebar in a stale view
until the next identity change.
Add `LoginPlugin.onUserFetched(userInfo, ctx)` and call it inside
`fetchUserInfo` after the server confirms identity but before
returning. Also commit the identity to `userAtom` storage here so
localStorage's identity marker is in lockstep with whatever caches
the plugin seeds — the predicate's first evaluation then sees a
consistent view rather than the prior session's data.
Errors thrown from the hook are swallowed and logged; they never
block fetchUserInfo.
