Extract shared data grid, selection bar, file dropzone and genre picker components

Track lists and the upload queue now render through a declarative DataGrid, the album editor reuses AlbumForm with a split layout and a track picker, and genre labels and types are shared helpers.

web-player/src/routes/(app)/library/albums/new/+page.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
 	import { goto } from '$app/navigation';
+	import { page } from '$app/state';
 	import LibraryAlbumEditor from '$lib/components/music/library/LibraryAlbumEditor.svelte';
 
 	let { data, form } = $props();
@@ -8,6 +9,7 @@
 <div class="mt-4">
 	<LibraryAlbumEditor
 		album={null}
+		artist={page.data.user?.name ?? ''}
 		tracks={data.tracks.items}
 		memberIds={[]}
 		formMessage={form?.action === 'saveAlbum' ? form.message : undefined}