feat(web): DiscoverResultCard attribution prop for M5c suggestions

web/src/lib/components/DiscoverResultCard.svelte

@@ -12,6 +12,7 @@
     subtitle,
     imageUrl,
     state,
+    attribution,
     onRequest,
   }: {
     kind: DiscoverCardKind;
@@ -19,6 +20,7 @@
     subtitle?: string;
     imageUrl?: string;
     state: DiscoverCardState;
+    attribution?: string;
     onRequest?: () => void;
   } = $props();
 
@@ -55,6 +57,11 @@
     {#if subtitle}
       <div class="subtitle text-sm text-text-secondary">{subtitle}</div>
     {/if}
+    {#if attribution}
+      <div class="attribution text-xs italic text-text-secondary" data-testid="attribution">
+        {attribution}
+      </div>
+    {/if}
     <div class="badge-row" data-testid="badge-row">
       {#if state === 'kept'}
         <span class="kept-pill" role="status">Kept</span>

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

@@ -104,4 +104,25 @@ describe('DiscoverResultCard', () => {
     // Lucide renders an inline <svg>; verify its presence as a proxy for "fallback rendered"
     expect(container.querySelector('svg')).toBeInTheDocument();
   });
+
+  test('renders attribution line when prop is set', () => {
+    render(DiscoverResultCard, {
+      props: {
+        kind: 'artist',
+        title: 'Outsider',
+        state: 'requestable',
+        attribution: 'Because you liked Boards of Canada and played Aphex Twin.'
+      }
+    });
+    expect(screen.getByTestId('attribution')).toHaveTextContent(
+      'Because you liked Boards of Canada and played Aphex Twin.'
+    );
+  });
+
+  test('omits attribution line when prop is absent', () => {
+    render(DiscoverResultCard, {
+      props: { kind: 'artist', title: 'Outsider', state: 'requestable' }
+    });
+    expect(screen.queryByTestId('attribution')).not.toBeInTheDocument();
+  });
 });