feat(web): add home/albums/artists API clients for M6a

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/lib/api/albums.ts

@@ -0,0 +1,22 @@
+import { createInfiniteQuery } from '@tanstack/svelte-query';
+import { api } from './client';
+import { qk } from './queries';
+import type { AlbumRef, Page } from './types';
+
+export const ALBUM_PAGE_SIZE = 50;
+
+export async function listAlbumsAlpha(limit: number, offset: number): Promise<Page<AlbumRef>> {
+  return api.get<Page<AlbumRef>>(`/api/library/albums?limit=${limit}&offset=${offset}`);
+}
+
+export function createAlbumsAlphaInfiniteQuery() {
+  return createInfiniteQuery({
+    queryKey: qk.albumsAlpha(),
+    queryFn: ({ pageParam = 0 }) => listAlbumsAlpha(ALBUM_PAGE_SIZE, pageParam),
+    initialPageParam: 0,
+    getNextPageParam: (last) => {
+      const loaded = last.offset + last.items.length;
+      return loaded >= last.total ? undefined : loaded;
+    }
+  });
+}