docs(filters): correct the split-context comment

The prior wording claimed NotificationsPanel subscribes to actions only, but it
reads filters (spreads them into setFilters). No consumer is actions-only today;
describe the split's intent without the wrong example.

frontend/src/components/FeedFiltersProvider.tsx

@@ -17,10 +17,10 @@ import { accountKey, LS, readJSON, readMerged, writeJSON } from "../lib/storage"
 // through the tree. Mirrors NavigationProvider (split contexts + one-line hooks); composed in
 // main.tsx inside NavigationProvider, around <App/>.
 //
-// TWO contexts on purpose: a STABLE actions context (setFilters never changes reference) and a
+// TWO contexts on purpose (mirrors NavigationProvider): a STABLE actions context (setFilters never
-// CHANGING state context (the filters object). Context consumers re-render when their value changes,
+// changes reference) and a CHANGING state context (the filters object). Context consumers re-render
-// so a component that only mutates filters (e.g. NotificationsPanel) subscribes to actions ONLY and
+// only when the context they read changes — so a component that dispatches filter changes without
-// doesn't re-render on every filter tweak.
+// reading the current filters can subscribe to actions ONLY and skip re-rendering on every tweak.
 //
 // SCOPE NOTE: this owns the FEED's filters only. The channel detail page keeps its OWN isolated
 // filter state (ChannelPage) — it renders a channel-scoped catalog, not the global feed — and the