feat(nav): N1 — collapsible left nav sidebar (Design C)

Move the modules (Feed/Channels/Playlists/Stats) out of the avatar dropdown into a
persistent left sidebar with icon+label entries; collapses to a thin icon rail
(persisted in localStorage). Account actions (About, Sign out, admin badge) move to a
popover at the sidebar bottom; Settings is a rail entry. Header is now a contextual top
bar (sync status, feed scope + search or page title, language, notifications) — logo and
account menu removed from it. New nav.json strings (HU/EN/DE). First step of Epic N.

frontend/src/components/Header.tsx

@@ -1,22 +1,20 @@
-import { useRef, useState } from "react";
 import { useTranslation } from "react-i18next";
-import { BarChart3, Home, Info, Library, ListVideo, LogOut, Search, Settings, Shield, Tv, User } from "lucide-react";
+import { Library, Search, User } from "lucide-react";
 import type { FeedFilters, Me } from "../lib/api";
 import type { Page } from "../lib/urlState";
 import { type LangCode } from "../i18n";
 import SyncStatus from "./SyncStatus";
 import NotificationCenter from "./NotificationCenter";
 import LanguageSwitcher from "./LanguageSwitcher";
-import AvatarImg from "./Avatar";
 
+// Contextual top bar. Primary navigation + account now live in the left NavSidebar; the
+// header carries the global sync status, the feed's scope toggle + search (or the current
+// page title), the language switcher and the notification bell.
 export default function Header({
   me,
   filters,
   setFilters,
   page,
-  setPage,
-  onOpenSettings,
-  onOpenAbout,
   onChangeLanguage,
   onGoToFullHistory,
 }: {
@@ -24,29 +22,13 @@ export default function Header({
   filters: FeedFilters;
   setFilters: (f: FeedFilters) => void;
   page: Page;
-  setPage: (p: Page) => void;
-  onOpenSettings: () => void;
-  onOpenAbout: () => void;
   onChangeLanguage: (code: LangCode) => void;
   onGoToFullHistory: () => void;
 }) {
   const { t, i18n } = useTranslation();
 
-  async function logout() {
-    await fetch("/auth/logout", { method: "POST", credentials: "include" });
-    location.reload();
-  }
-
   return (
     <header className="h-14 shrink-0 border-b border-border bg-surface/95 flex items-center gap-3 px-4 z-20">
-      <button
-        onClick={() => setPage("feed")}
-        className="text-xl font-bold tracking-tight select-none"
-        title={t("header.feed")}
-      >
-        Sift<span className="text-accent">lode</span>
-      </button>
-
       <SyncStatus isAdmin={me.role === "admin"} onGoToFullHistory={onGoToFullHistory} />
 
       {page === "feed" && (
@@ -101,130 +83,7 @@ export default function Header({
       <div className="flex items-center gap-1">
         <LanguageSwitcher value={i18n.language as LangCode} onChange={onChangeLanguage} />
         <NotificationCenter filters={filters} setFilters={setFilters} />
-        <div className="pl-1">
-          <AccountMenu
-            me={me}
-            logout={logout}
-            page={page}
-            setPage={setPage}
-            onOpenSettings={onOpenSettings}
-            onOpenAbout={onOpenAbout}
-          />
-        </div>
       </div>
     </header>
   );
 }
-
-function Avatar({ me, className = "" }: { me: Me; className?: string }) {
-  return (
-    <AvatarImg
-      src={me.avatar_url}
-      fallback={me.display_name ?? me.email}
-      className={`rounded-full ${className}`}
-    />
-  );
-}
-
-function AccountMenu({
-  me,
-  logout,
-  page,
-  setPage,
-  onOpenSettings,
-  onOpenAbout,
-}: {
-  me: Me;
-  logout: () => void;
-  page: Page;
-  setPage: (p: Page) => void;
-  onOpenSettings: () => void;
-  onOpenAbout: () => void;
-}) {
-  const { t } = useTranslation();
-  const [open, setOpen] = useState(false);
-  const closeTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
-
-  function openNow() {
-    if (closeTimer.current) clearTimeout(closeTimer.current);
-    setOpen(true);
-  }
-  function closeSoon() {
-    closeTimer.current = setTimeout(() => setOpen(false), 220);
-  }
-
-  const itemClass =
-    "w-full flex items-center gap-2 text-sm px-2 py-2 rounded-lg text-muted hover:text-fg hover:bg-card transition";
-
-  return (
-    <div className="relative" onMouseEnter={openNow} onMouseLeave={closeSoon}>
-      <button
-        onClick={() => setOpen((o) => !o)}
-        title={me.email}
-        className="block rounded-full ring-2 ring-transparent hover:ring-border focus:outline-none focus:ring-accent transition"
-      >
-        <Avatar me={me} className="w-8 h-8 text-xs" />
-      </button>
-
-      {open && (
-        <div className="glass absolute right-0 mt-2 w-64 rounded-xl p-3 z-30 animate-[popIn_0.16s_ease]">
-          <div className="flex items-center gap-3 pb-3 border-b border-border">
-            <Avatar me={me} className="w-10 h-10 text-sm shrink-0" />
-            <div className="min-w-0">
-              <div className="text-sm font-semibold truncate">
-                {me.display_name ?? me.email.split("@")[0]}
-              </div>
-              <div className="text-xs text-muted truncate">{me.email}</div>
-            </div>
-          </div>
-
-          {me.role === "admin" && (
-            <div className="flex items-center gap-1.5 mt-2 text-[11px] font-medium text-accent">
-              <Shield className="w-3.5 h-3.5" />
-              {t("header.account.admin")}
-            </div>
-          )}
-
-          <div className="mt-2 flex flex-col">
-            {page !== "feed" && (
-              <button onClick={() => { setPage("feed"); setOpen(false); }} className={itemClass}>
-                <Home className="w-4 h-4" />
-                {t("header.account.feed")}
-              </button>
-            )}
-            {page !== "channels" && (
-              <button onClick={() => { setPage("channels"); setOpen(false); }} className={itemClass}>
-                <Tv className="w-4 h-4" />
-                {t("header.account.channels")}
-              </button>
-            )}
-            {page !== "playlists" && (
-              <button onClick={() => { setPage("playlists"); setOpen(false); }} className={itemClass}>
-                <ListVideo className="w-4 h-4" />
-                {t("header.account.playlists")}
-              </button>
-            )}
-            {me.role === "admin" && page !== "stats" && (
-              <button onClick={() => { setPage("stats"); setOpen(false); }} className={itemClass}>
-                <BarChart3 className="w-4 h-4" />
-                {t("header.account.stats")}
-              </button>
-            )}
-            <button onClick={() => { onOpenSettings(); setOpen(false); }} className={itemClass}>
-              <Settings className="w-4 h-4" />
-              {t("header.account.settings")}
-            </button>
-            <button onClick={() => { onOpenAbout(); setOpen(false); }} className={itemClass}>
-              <Info className="w-4 h-4" />
-              {t("header.account.about")}
-            </button>
-            <button onClick={logout} className={itemClass}>
-              <LogOut className="w-4 h-4" />
-              {t("header.account.signOut")}
-            </button>
-          </div>
-        </div>
-      )}
-    </div>
-  );
-}