feat(12-02): remove Libraries sidebar nav item and view routing

- Remove 'libraries' from View type union in app-sidebar.ts
- Remove Libraries nav item from sidebar navigation list
- Remove case 'libraries' view routing in index.ts
- Remove library-manager component import from index.ts

frontend/index.ts

@@ -5,7 +5,6 @@ import '@components/now-playing/now-playing.ts';
 import '@components/sidebar/app-sidebar.ts';
 import '@components/queue-panel/queue-panel.ts';
 import '@components/playlist-view/playlist-view.ts';
-import '@components/library-manager/library-manager.ts';
 import '@components/config-page/config-page.ts';
 import '@components/artists-view/artists-view.ts';
 import '@components/artist-details/artist-details.ts';
@@ -92,9 +91,6 @@ document.addEventListener('navigate', (e: Event) => {
             mainContent.appendChild(genreEl);
             break;
         }
-        case 'libraries':
-            mainContent.innerHTML = '<library-manager></library-manager>';
-            break;
         case 'settings':
             mainContent.innerHTML = '<config-page></config-page>';
             break;

frontend/src/components/sidebar/app-sidebar.ts

@@ -5,7 +5,7 @@ import { designTokens } from '../../styles/tokens.css';
 
 import type { DragActiveDetail } from '@utils/drag-controller';
 
-type View = 'home' | 'libraries' | 'playlists' | 'artists' | 'genres' | 'albums' | 'tracks' | 'settings';
+type View = 'home' | 'playlists' | 'artists' | 'genres' | 'albums' | 'tracks' | 'settings';
 
 interface NavItem {
     id: View;
@@ -143,7 +143,6 @@ export class AppSidebar extends LitElement {
 
     private navItems: NavItem[] = [
         { id: 'home', label: 'Home', icon: 'house' },
-        { id: 'libraries', label: 'Libraries', icon: 'folder-open' },
         { id: 'playlists', label: 'Playlists', icon: 'list' },
         { id: 'artists', label: 'Artists', icon: 'user-group' },
         { id: 'genres', label: 'Genres', icon: 'masks-theater' },