feat(ui): add Storybook design system refinements

frontend/src/components/EntryRow.stories.jsx

@@ -0,0 +1,66 @@
+import EntryRow from './EntryRow';
+
+export default {
+  component: EntryRow,
+  tags: ['autodocs'],
+};
+
+const sampleEntry = {
+  entry_uid: 'entry_123',
+  title: 'A Great Article About Web Design',
+  archived_at: '2026-06-27T10:30:00Z',
+  entity_kind: 'page',
+  source_kind: 'web',
+  total_artifact_bytes: 2048576,
+  original_url: 'https://example.com/article',
+  has_favicon: false,
+};
+
+const videoEntry = {
+  entry_uid: 'entry_456',
+  title: 'React Performance Tips',
+  archived_at: '2026-06-26T14:15:00Z',
+  entity_kind: 'video',
+  source_kind: 'youtube',
+  total_artifact_bytes: 104857600,
+  original_url: 'https://youtube.com/watch?v=xyz',
+  has_favicon: false,
+};
+
+export const Default = {
+  args: {
+    entry: sampleEntry,
+    archiveId: 'archive_1',
+    isSelected: false,
+    onSelect: () => {},
+  },
+  decorators: [
+    (Story) => (
+      <div style={{
+        display: 'grid',
+        gridTemplateColumns: '178px 38% 130px 110px 34%',
+        gap: '10px',
+        padding: '10px',
+        background: 'var(--paper-3)',
+      }}>
+        <Story />
+      </div>
+    ),
+  ],
+};
+
+export const Selected = {
+  args: {
+    ...Default.args,
+    isSelected: true,
+  },
+  decorators: Default.decorators,
+};
+
+export const Video = {
+  args: {
+    ...Default.args,
+    entry: videoEntry,
+  },
+  decorators: Default.decorators,
+};