feat(web): add ArtistRow component

One row in the artists list: avatar initial, name, album count,
chevron. Entire row is an <a> for click + keyboard activation.

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

@@ -0,0 +1,29 @@
+import { describe, expect, test } from 'vitest';
+import { render, screen } from '@testing-library/svelte';
+import ArtistRow from './ArtistRow.svelte';
+import type { ArtistRef } from '$lib/api/types';
+
+const artist: ArtistRef = { id: 'abc', name: 'alice', album_count: 12 };
+
+describe('ArtistRow', () => {
+  test('renders initial, name, album count inside a link to /artists/:id', () => {
+    render(ArtistRow, { props: { artist } });
+
+    const link = screen.getByRole('link');
+    expect(link).toHaveAttribute('href', '/artists/abc');
+    expect(link).toHaveTextContent('alice');
+    expect(link).toHaveTextContent('12 albums');
+    expect(link).toHaveTextContent('A'); // initial letter
+  });
+
+  test('singular "1 album" when album_count is 1', () => {
+    render(ArtistRow, { props: { artist: { ...artist, album_count: 1 } } });
+    expect(screen.getByRole('link')).toHaveTextContent('1 album');
+  });
+
+  test('empty name still renders a safe initial', () => {
+    render(ArtistRow, { props: { artist: { ...artist, name: '' } } });
+    // No crash; initial container present but empty or a placeholder char.
+    expect(screen.getByRole('link')).toBeInTheDocument();
+  });
+});