Each use case is a small product scenario where the signal API feature
is the natural tool, not a pure API demo:

- UC28 Server log viewer — EffectContext.isBackgroundChange() pulses
  for server-driven inserts but not for user dropdown edits.
- UC29 Profile auto-save — Signal.untracked keeps audit attribution
  stable when admins are swapped mid-session; Signal.unboundEffect
  ships audit entries without holding the session lock.
- UC30 Catalog filter — Signal.cached lets grid + count badge +
  export button share one filter pass over 1 000 products.
- UC31 Seat reservation — ValueSignal.replace gives one winner per
  seat under concurrent claim; update(old + 1) keeps the day's
  reservation tally consistent under burst admin traffic.
- UC32 Mutable vs immutable form — same onboarding form bound to a
  JPA-style Customer (modifier+setter) and immutable CustomerDto
  (updater+withX); modify/update each fire one notification.
- UC33 Stable selection — id-based equality on the selection signal
  stops the details pane's open animation from replaying when the
  server pushes a status update to the already-selected order.
- UC34 Feature flag service — FeatureFlagService bean exposes
  Signal<Boolean> via asReadonly(); flips go through service methods.
- UC35 Kanban column — ListSignal.moveTo preserves entry signal
  identity through reorders; insertAllFirst/insertAllAt bulk-insert
  with a single change notification.

HomeView lists the new category; styles.css gets a generic flash
animation used by UC28.