feat(web): top-bar centered nav + Library tab page (replace sidebar)

Operator 2026-06-01: "navigation layout and library sections are
what I'd like to have implemented as it seems better than our
current navbar solution. I think I'd like to have these nav options
moved into the top bar centered."

Top-bar restructure:
- Centered nav (replaces the 192dp left sidebar): Home / Library /
  Discover, with icons + labels. Labels collapse below sm breakpoint
  so the bar stays icon-only on small viewports.
- Right side (search input + user dropdown) unchanged.
- Hamburger button + MobileNavDrawer + the mobileNav store all
  removed - the centered nav lives at all viewport sizes.

Library page restructure (mirrors Android LibraryScreen):
- New routes/library/+layout.svelte renders a tab bar across the
  five Library sub-pages: Artists / Albums / Liked / History /
  Playlists. Active tab gets an accent underline + onSurface text.
- routes/library/+page.server.ts redirects bare /library to
  /library/artists (Android default tab).
- /playlists (list) moved to /library/playlists; old URL gets a 308
  redirect (routes/playlists/+page.server.ts) so existing bookmarks
  land on the new location. /playlists/[id] (detail) is unchanged -
  matches the server API URL shape.

Deleted: Shell's sidebar markup, MobileNavDrawer.{svelte,test.ts},
the mobileNav store, the old routes/playlists/+page.svelte. Shell
test rewritten to assert the new 3-item centered nav; playlists
test moved next to its new +page.svelte and its test-utils import
path updated.

web/src/lib/components/MobileNavDrawer.svelte

@@ -1,141 +0,0 @@
-<script lang="ts">
-  import { X } from 'lucide-svelte';
-  import { page } from '$app/state';
-  import { goto } from '$app/navigation';
-  import { user, logout } from '$lib/auth/store.svelte';
-  import { mobileNav, closeMobileNav } from '$lib/stores/mobileNav.svelte';
-
-  let previouslyFocused: HTMLElement | null = null;
-  let drawerEl: HTMLElement | undefined = $state();
-
-  const navItems = [
-    { href: '/',                label: 'Home' },
-    { href: '/library/artists', label: 'Artists' },
-    { href: '/library/albums',  label: 'Albums' },
-    { href: '/library/liked',   label: 'Liked' },
-    { href: '/library/history', label: 'History' },
-    { href: '/discover',        label: 'Discover' },
-    { href: '/playlists',       label: 'Playlists' }
-  ];
-
-  function isActive(href: string): boolean {
-    if (href === '/') return page.url.pathname === '/';
-    return page.url.pathname.startsWith(href);
-  }
-
-  async function handleLogout() {
-    closeMobileNav();
-    await logout();
-    goto('/login', { replaceState: true });
-  }
-
-  function onLinkClick() {
-    closeMobileNav();
-  }
-
-  $effect(() => {
-    if (mobileNav.value) {
-      previouslyFocused = document.activeElement as HTMLElement | null;
-      Promise.resolve().then(() => {
-        const first = drawerEl?.querySelector<HTMLAnchorElement>('nav a');
-        first?.focus();
-      });
-    } else if (previouslyFocused) {
-      previouslyFocused.focus();
-      previouslyFocused = null;
-    }
-  });
-
-  function onKeydown(e: KeyboardEvent) {
-    if (mobileNav.value && e.key === 'Escape') {
-      closeMobileNav();
-    }
-  }
-</script>
-
-<svelte:window onkeydown={onKeydown} />
-
-{#if mobileNav.value}
-  <button
-    type="button"
-    aria-label="Close navigation backdrop"
-    class="fixed inset-0 bg-obsidian/40 z-40 md:hidden"
-    onclick={() => closeMobileNav()}
-  ></button>
-{/if}
-
-<aside
-  bind:this={drawerEl}
-  aria-label="Main navigation"
-  aria-hidden={!mobileNav.value}
-  inert={!mobileNav.value}
-  class="fixed top-0 left-0 h-full w-[min(280px,80vw)] bg-surface z-50 md:hidden
-         transition-transform duration-200 flex flex-col
-         motion-reduce:transition-none
-         {mobileNav.value ? 'translate-x-0' : '-translate-x-full'}"
->
-  <div class="flex items-center justify-between border-b border-border px-4 py-3">
-    <h2 class="text-lg font-semibold">Navigate</h2>
-    <button
-      type="button"
-      aria-label="Close navigation"
-      onclick={() => closeMobileNav()}
-      class="text-text-secondary hover:text-text-primary min-h-[44px] min-w-[44px]
-             flex items-center justify-center"
-    >
-      <X size={20} />
-    </button>
-  </div>
-
-  <nav class="flex-1 overflow-y-auto p-2">
-    <ul>
-      {#each navItems as item (item.href)}
-        <li>
-          <a
-            href={item.href}
-            onclick={onLinkClick}
-            class="flex items-center min-h-[44px] rounded px-3 py-2 hover:bg-surface-hover"
-            aria-current={isActive(item.href) ? 'page' : undefined}
-          >
-            {item.label}
-          </a>
-        </li>
-      {/each}
-    </ul>
-
-    <hr class="my-2 border-border" />
-
-    <ul>
-      <li>
-        <a
-          href="/settings"
-          onclick={onLinkClick}
-          class="flex items-center min-h-[44px] rounded px-3 py-2 hover:bg-surface-hover"
-        >
-          Settings
-        </a>
-      </li>
-      {#if user.value?.is_admin}
-        <li>
-          <a
-            href="/admin"
-            onclick={onLinkClick}
-            class="flex items-center min-h-[44px] rounded px-3 py-2 hover:bg-surface-hover"
-          >
-            Admin
-          </a>
-        </li>
-      {/if}
-      <li>
-        <button
-          type="button"
-          onclick={handleLogout}
-          class="flex w-full items-center min-h-[44px] rounded px-3 py-2 text-left
-                 hover:bg-surface-hover"
-        >
-          Log out
-        </button>
-      </li>
-    </ul>
-  </nav>
-</aside>

web/src/lib/components/MobileNavDrawer.test.ts

@@ -1,65 +0,0 @@
-import { describe, it, expect, beforeEach, vi } from 'vitest';
-import { render, screen } from '@testing-library/svelte';
-
-// SvelteKit's $app/state and $app/navigation can't be imported in vitest
-// without bootstrapping the runtime; stub them. Mirrors the pattern used
-// by Shell.test.ts and other route tests.
-vi.mock('$app/state', () => ({
-  page: { url: new URL('http://localhost/') }
-}));
-
-vi.mock('$app/navigation', () => ({
-  goto: vi.fn()
-}));
-
-// auth/store reads $app — stub the bits MobileNavDrawer touches.
-vi.mock('$lib/auth/store.svelte', () => ({
-  user: { value: { username: 'alice', is_admin: false } },
-  logout: vi.fn().mockResolvedValue(undefined)
-}));
-
-import MobileNavDrawer from './MobileNavDrawer.svelte';
-import { mobileNav, openMobileNav, closeMobileNav } from '$lib/stores/mobileNav.svelte';
-
-describe('MobileNavDrawer', () => {
-  beforeEach(() => {
-    closeMobileNav();
-  });
-
-  it('renders inert + aria-hidden when closed', () => {
-    render(MobileNavDrawer);
-    const aside = screen.getByLabelText('Main navigation');
-    expect(aside.getAttribute('aria-hidden')).toBe('true');
-    // Svelte 5 + jsdom binds `inert` as a property, not always as an
-    // attribute. Mirror the pattern used in QueueDrawer.test.ts.
-    const inertProp = (aside as unknown as { inert?: boolean }).inert === true;
-    const inertAttr = aside.hasAttribute('inert');
-    expect(inertProp || inertAttr).toBe(true);
-  });
-
-  it('flips to visible when mobileNav opens', async () => {
-    render(MobileNavDrawer);
-    openMobileNav();
-    await Promise.resolve();
-    const aside = screen.getByLabelText('Main navigation');
-    expect(aside.getAttribute('aria-hidden')).toBe('false');
-    expect(aside.hasAttribute('inert')).toBe(false);
-  });
-
-  it('renders all nav items + Settings + Log out', () => {
-    openMobileNav();
-    render(MobileNavDrawer);
-    expect(screen.getByText('Home')).toBeInTheDocument();
-    expect(screen.getByText('Artists')).toBeInTheDocument();
-    expect(screen.getByText('Settings')).toBeInTheDocument();
-    expect(screen.getByText('Log out')).toBeInTheDocument();
-  });
-
-  it('Escape key closes the drawer', () => {
-    openMobileNav();
-    render(MobileNavDrawer);
-    expect(mobileNav.value).toBe(true);
-    window.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape' }));
-    expect(mobileNav.value).toBe(false);
-  });
-});

web/src/lib/components/Shell.svelte

@@ -1,14 +1,12 @@
 <script lang="ts">
   import { page } from '$app/state';
   import { goto } from '$app/navigation';
-  import { ChevronDown, Menu } from 'lucide-svelte';
+  import { ChevronDown, Compass, House, LibraryBig } from 'lucide-svelte';
   import { user, logout } from '$lib/auth/store.svelte';
   import { player } from '$lib/player/store.svelte';
   import { appName } from '$lib/branding';
   import PlayerBar from './PlayerBar.svelte';
   import SearchInput from './SearchInput.svelte';
-  import MobileNavDrawer from './MobileNavDrawer.svelte';
-  import { toggleMobileNav } from '$lib/stores/mobileNav.svelte';
 
   let { children } = $props<{ children: import('svelte').Snippet }>();
 
@@ -43,39 +41,46 @@
     return page.url.pathname.startsWith(href);
   }
 
-  // Search reaches /search via the global SearchInput in the header (not the
-  // nav). Requests is a tab inside Discover. Settings + Admin live in the
-  // username dropdown — they're per-operator chrome, not primary surfaces.
+  // Primary nav. Sits centered in the top bar (replaces the prior left
+  // sidebar). Mirrors the Android top-app-bar treatment: three first-class
+  // destinations, plus Library acting as a parent for Artists / Albums /
+  // Liked / History / Playlists (tabs at /library/+layout.svelte).
+  // Search + user menu live on the right side of the header (unchanged).
   const navItems = [
-    { href: '/',                label: 'Home' },
-    { href: '/library/artists', label: 'Artists' },
-    { href: '/library/albums',  label: 'Albums' },
-    { href: '/library/liked',   label: 'Liked' },
-    { href: '/library/history', label: 'History' },
-    { href: '/discover',        label: 'Discover' },
-    { href: '/playlists',       label: 'Playlists' }
+    { href: '/',          label: 'Home',     icon: House },
+    { href: '/library',   label: 'Library',  icon: LibraryBig },
+    { href: '/discover',  label: 'Discover', icon: Compass }
   ];
 </script>
 
 <svelte:window onclick={handleWindowClick} onkeydown={(e) => e.key === 'Escape' && (menuOpen = false)} />
 
-<div class="grid h-screen grid-cols-[auto_1fr] grid-rows-[auto_1fr_auto] bg-background text-text-primary">
-  <header class="col-span-2 flex items-center gap-2 md:gap-4 border-b border-border bg-surface px-3 md:px-4 py-3">
-    <button
-      type="button"
-      aria-label="Open navigation"
-      onclick={toggleMobileNav}
-      class="md:hidden flex items-center justify-center min-h-[44px] min-w-[44px] -ml-1
-             rounded text-text-secondary hover:text-text-primary
-             focus-visible:ring-2 focus-visible:ring-accent"
-    >
-      <Menu size={22} strokeWidth={1.5} />
-    </button>
-    <div class="font-semibold text-sm md:text-base">{appName()}</div>
-    <div class="flex-1 min-w-0">
+<div class="grid h-screen grid-rows-[auto_1fr_auto] bg-background text-text-primary">
+  <header class="flex items-center gap-3 md:gap-6 border-b border-border bg-surface px-3 md:px-4 py-2">
+    <a href="/" class="font-semibold text-sm md:text-base whitespace-nowrap">{appName()}</a>
+
+    <nav aria-label="Primary" class="flex flex-1 items-center justify-center gap-1 md:gap-2">
+      {#each navItems as item}
+        {@const active = isActive(item.href)}
+        <a
+          href={item.href}
+          class="group flex items-center gap-2 rounded px-2 md:px-3 py-2 min-h-[44px]
+                 text-text-secondary hover:text-text-primary hover:bg-surface-hover
+                 focus-visible:ring-2 focus-visible:ring-accent
+                 {active ? 'text-text-primary bg-surface-hover' : ''}"
+          aria-current={active ? 'page' : undefined}
+        >
+          <item.icon size={18} strokeWidth={1.75} aria-hidden="true" />
+          <span class="hidden sm:inline">{item.label}</span>
+        </a>
+      {/each}
+    </nav>
+
+    <div class="hidden md:block min-w-0 max-w-xs flex-shrink">
       <SearchInput />
     </div>
-    <div class="relative">
+
+    <div class="relative flex-shrink-0">
       <button
         bind:this={menuButtonRef}
         type="button"
@@ -130,31 +135,11 @@
     </div>
   </header>
 
-  <nav class="hidden w-48 border-r border-border bg-surface md:block">
-    <ul class="p-2">
-      {#each navItems as item}
-        <li>
-          <a
-            href={item.href}
-            class="block rounded px-3 py-2 hover:bg-surface-hover"
-            aria-current={isActive(item.href) ? 'page' : undefined}
-          >
-            {item.label}
-          </a>
-        </li>
-      {/each}
-    </ul>
-  </nav>
-
-  <main class="overflow-y-auto p-4 md:col-start-2">
+  <main class="overflow-y-auto p-4">
     {@render children?.()}
   </main>
 
   {#if player.current}
-    <div class="col-span-2">
-      <PlayerBar />
-    </div>
+    <PlayerBar />
   {/if}
 </div>
-
-<MobileNavDrawer />

web/src/lib/components/Shell.test.ts

@@ -39,30 +39,35 @@ describe('Shell', () => {
     expect(screen.getByText('alice')).toBeInTheDocument();
   });
 
-  test('main nav renders the six primary surfaces in order', () => {
+  test('main nav renders the three primary surfaces in order', () => {
     render(Shell);
-    const labels = ['Home', 'Artists', 'Albums', 'Liked', 'Discover', 'Playlists'];
+    // Library is a parent for Artists / Albums / Liked / History /
+    // Playlists (tabs under /library); only the parent appears here.
+    const labels = ['Home', 'Library', 'Discover'];
     for (const label of labels) {
       expect(screen.getByRole('link', { name: label })).toBeInTheDocument();
     }
     expect(screen.getByRole('link', { name: 'Home' })).toHaveAttribute('href', '/');
-    expect(screen.getByRole('link', { name: 'Artists' })).toHaveAttribute('href', '/library/artists');
-    expect(screen.getByRole('link', { name: 'Albums' })).toHaveAttribute('href', '/library/albums');
+    expect(screen.getByRole('link', { name: 'Library' })).toHaveAttribute('href', '/library');
     expect(screen.getByRole('link', { name: 'Discover' })).toHaveAttribute('href', '/discover');
-    expect(screen.getByRole('link', { name: 'Playlists' })).toHaveAttribute('href', '/playlists');
   });
 
-  test('main nav omits Search, Requests, Hidden, Settings, and Admin', () => {
+  test('main nav omits Artists/Albums/Liked/History/Playlists/Search/Settings/Admin', () => {
     userState.current = { id: '1', username: 'alice', is_admin: true };
     render(Shell);
-    // Search reaches /search via the global SearchInput, Requests is a
-    // tab inside Discover, Hidden lives under Settings, Settings + Admin
-    // live in the username dropdown — none belong on the main nav.
+    // Library sub-pages reach their content via the /library tab bar
+    // (in routes/library/+layout.svelte), not via the global Shell nav.
+    // Search reaches /search via the global SearchInput on the right.
+    // Settings + Admin live in the username dropdown — they're per-
+    // operator chrome, not primary surfaces.
     const navLinks = screen
       .getAllByRole('link')
-      .filter((el) => el.closest('nav') !== null)
+      .filter((el) => el.closest('nav[aria-label="Primary"]') !== null)
       .map((el) => el.textContent?.trim());
-    for (const label of ['Search', 'Requests', 'Hidden', 'Settings', 'Admin']) {
+    for (const label of [
+      'Artists', 'Albums', 'Liked', 'History', 'Playlists',
+      'Search', 'Requests', 'Hidden', 'Settings', 'Admin'
+    ]) {
       expect(navLinks).not.toContain(label);
     }
   });

web/src/lib/stores/mobileNav.svelte.ts

@@ -1,22 +0,0 @@
-// Open/close state for the off-canvas mobile navigation drawer.
-// Mounted once from Shell.svelte; toggled by the hamburger button.
-
-let _open = $state(false);
-
-export const mobileNav = {
-  get value(): boolean {
-    return _open;
-  }
-};
-
-export function openMobileNav(): void {
-  _open = true;
-}
-
-export function closeMobileNav(): void {
-  _open = false;
-}
-
-export function toggleMobileNav(): void {
-  _open = !_open;
-}

web/src/routes/library/+layout.svelte

@@ -0,0 +1,45 @@
+<script lang="ts">
+  import { page } from '$app/state';
+
+  let { children } = $props<{ children: import('svelte').Snippet }>();
+
+  // Tab bar for the Library section. Mirrors Android's LibraryScreen
+  // (artists / albums / liked / history / playlists) — Playlists lives
+  // here so the operator can find their personal collection in one
+  // place rather than tracking a separate top-level route.
+  const tabs = [
+    { href: '/library/artists',   label: 'Artists' },
+    { href: '/library/albums',    label: 'Albums' },
+    { href: '/library/liked',     label: 'Liked' },
+    { href: '/library/history',   label: 'History' },
+    { href: '/library/playlists', label: 'Playlists' }
+  ];
+
+  function isActiveTab(href: string): boolean {
+    return page.url.pathname === href || page.url.pathname.startsWith(href + '/');
+  }
+</script>
+
+<div class="space-y-4">
+  <nav aria-label="Library sections" class="border-b border-border">
+    <ul class="flex gap-1 overflow-x-auto">
+      {#each tabs as tab}
+        {@const active = isActiveTab(tab.href)}
+        <li>
+          <a
+            href={tab.href}
+            class="block px-3 md:px-4 py-3 text-sm whitespace-nowrap border-b-2
+                   {active
+                     ? 'border-accent text-text-primary'
+                     : 'border-transparent text-text-secondary hover:text-text-primary'}"
+            aria-current={active ? 'page' : undefined}
+          >
+            {tab.label}
+          </a>
+        </li>
+      {/each}
+    </ul>
+  </nav>
+
+  {@render children?.()}
+</div>

web/src/routes/library/+page.server.ts

@@ -0,0 +1,9 @@
+import { redirect } from '@sveltejs/kit';
+
+// /library has no content of its own — the tab bar (in +layout.svelte)
+// always renders the active sub-page. Bare hits go to the default tab
+// (Artists, matching Android's LibraryScreen default). 308 = permanent
+// + preserve method, so SPA navigations and direct loads behave the same.
+export const load = () => {
+  throw redirect(308, '/library/artists');
+};

web/src/routes/library/playlists/+page.svelte

@@ -32,6 +32,8 @@
     try {
       const p = await createPlaylist({ name: newName.trim() });
       await queryClient.invalidateQueries({ queryKey: qk.playlists() });
+      // Detail route stays at /playlists/[id] (matches the API URL);
+      // only the LIST view moved under /library.
       goto(`/playlists/${p.id}`);
     } catch (e: unknown) {
       createError = (e as { message?: string })?.message ?? 'Could not create.';
@@ -43,11 +45,11 @@
   }
 </script>
 
-<svelte:head><title>{pageTitle('Playlists')}</title></svelte:head>
+<svelte:head><title>{pageTitle('Library · Playlists')}</title></svelte:head>
 
-<div class="mx-auto max-w-6xl px-4 py-6">
-  <header class="mb-6 flex items-center justify-between">
-    <h1 class="text-2xl font-medium text-text-primary">Playlists</h1>
+<div class="space-y-4">
+  <header class="flex items-center justify-between">
+    <h1 class="font-display text-2xl font-medium text-text-primary">Playlists</h1>
     <button
       type="button"
       onclick={() => (creating = true)}
@@ -59,7 +61,7 @@
   </header>
 
   {#if creating}
-    <div class="mb-6 rounded-md border border-border bg-surface p-4">
+    <div class="rounded-md border border-border bg-surface p-4">
       <label class="block text-sm font-medium text-text-primary">
         Name
         <input
@@ -99,7 +101,7 @@
   {:else if playlistsQuery?.isError}
     <ApiErrorBanner error={playlistsQuery.error} onRetry={() => playlistsQuery.refetch()} />
   {:else if playlistsQuery?.data}
-    <section class="mb-8">
+    <section>
       <h2 class="mb-3 text-sm font-medium uppercase tracking-wide text-text-muted">Your playlists</h2>
       {#if playlistsQuery.data.owned.length === 0}
         <p class="text-sm text-text-muted">No playlists yet. Click "New playlist" to start one.</p>

web/src/routes/library/playlists/playlists.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test, vi } from 'vitest';
 import { render, screen, fireEvent, waitFor } from '@testing-library/svelte';
-import { mockQuery } from '../../test-utils/query';
+import { mockQuery } from '../../../test-utils/query';
 import type { Playlist } from '$lib/api/types';
 
 vi.mock('$lib/api/playlists', () => ({

web/src/routes/playlists/+page.server.ts

@@ -0,0 +1,10 @@
+import { redirect } from '@sveltejs/kit';
+
+// /playlists (list) moved to /library/playlists on 2026-06-01 as part of
+// the nav restructure (Scribe 518). The detail route /playlists/[id]
+// still lives here at /routes/playlists/[id]/+page.svelte — that URL
+// matches the server API shape and is unchanged.
+// 308 = permanent + preserve method; old bookmarks land on the new URL.
+export const load = () => {
+  throw redirect(308, '/library/playlists');
+};