v3: src/ gets one layout rule and keeps to it — each layer holds one kind of module, and every layer is split into the same domains — the previous pass sorted components into folders but left hooks, helpers and a barrel inside them, kept hooks/, utils/ and contexts/ flat, and still grouped most tests by theme. The rule: components/ holds only components (.tsx), contexts/ holds FooContext.ts + FooProvider.tsx pairs, hooks/ every hook, utils/ every non-React module, pages/ one component per route and nothing else. Each of components/, contexts/, hooks/ and utils/ is split into the same domains — auth, category, chat, comment, dump, editor, feed, form, layout, player, playlist, profile, social, theme, ws — plus shared/ for what belongs to no one domain, so the chat is components/chat, contexts/chat, hooks/chat and utils/chat. components/ui becomes components/shared to match. Out of components/: useApiForm goes to hooks/form, chat's message.ts and time.ts to utils/chat (with chatDraft and chatText, now draft.ts and text.ts), the emoji skin tone to utils/editor, the remembered volume to utils/player; player/icons.tsx is PlayerIcons.tsx. components/form/index.ts is gone: everything is imported from its own file, FormProvider straight from react-hook-form, and expectOk sits beside friendlyFetchError in utils/shared/api.ts (apiError.ts), since pages that have no form used it too. Out of pages/: the index's feed views, tab bar and presence row move to components/feed; HotFeed and NewFeed, identical but for the sort, are one DumpFeed with an order prop, which also takes over MainFeedProps from pages/index/types.ts. App is a named export like everything else. Tests mirror the tree one file per module — test/<layer>/<domain>/<Module>.test.tsx — so the themed files (hooks/misc, data, editor, sync; utils/misc, text, storage, remote, journal; contexts/providers; pages/auth and UserSubpages; layout/Fabs) are split by subject, the setup each piece needs kept and the rest dropped; the floating-button test becomes one test per button, 627 tests now. The README states the rule. No behaviour changes; the catalogues only move their source references.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/hooks/feed/useDefaultFeedTab.ts

@@ -0,0 +1,32 @@
+import { useCallback, useState } from "react";
+import {
+  DEFAULT_FEED_TAB,
+  FEED_TABS,
+  type FeedTab,
+} from "../../config/feedTabs.ts";
+
+const STORAGE_KEY = "default-feed-tab";
+
+function readStored(): FeedTab {
+  const stored = localStorage.getItem(STORAGE_KEY);
+  return stored && (FEED_TABS as readonly string[]).includes(stored)
+    ? stored as FeedTab
+    : DEFAULT_FEED_TAB;
+}
+
+/**
+ * User preference for which feed tab the index opens on, persisted to
+ * localStorage (defaults to DEFAULT_FEED_TAB). Returns the stored tab and a setter that
+ * persists the choice. Consumers that only need to honour the preference (e.g.
+ * the index default) can ignore the setter.
+ */
+export function useDefaultFeedTab(): [FeedTab, (tab: FeedTab) => void] {
+  const [tab, setTabState] = useState<FeedTab>(readStored);
+
+  const setTab = useCallback((t: FeedTab) => {
+    localStorage.setItem(STORAGE_KEY, t);
+    setTabState(t);
+  }, []);
+
+  return [tab, setTab];
+}