feat(v028): NoteCard 이미지 <img> 렌더링 + onClick (openMedia 시그니처는 Task 3)

- 회색 placeholder div → <img src=inkling-media://...> 로 교체
- onClick 으로 inboxApi.openMedia(relPath) 호출 (현재는 InboxApi 인터페이스에 부재 → unknown cast 사용; Task 3 에서 정식 시그니처 추가 후 cast 제거 예정)
- alt='' 로 decorative 처리 (role=presentation), title 에 relPath 유지
- flex-wrap 추가 — 다수 이미지 시 줄바꿈

Tests: tests/unit/NoteCard.test.tsx 신규 2건 (img src 검증, click → openMedia 호출)
회귀: 468 → 470 pass

src/renderer/inbox/components/NoteCard.tsx

@@ -332,9 +332,23 @@ export function NoteCard({ note, onDeleted, onUpdated, mode = 'inbox', onRestore
       )}
 
       {local.media.length > 0 && (
-        <div style={{ marginTop: 10, display: 'flex', gap: 6 }}>
+        <div style={{ marginTop: 10, display: 'flex', flexWrap: 'wrap', gap: 6 }}>
           {local.media.map((m) => (
-            <div key={m.id} style={{ width: 48, height: 48, background: '#eee', borderRadius: 4 }} title={m.relPath} />
+            <img
+              key={m.id}
+              src={`inkling-media://${m.relPath}`}
+              alt=""
+              title={m.relPath}
+              onClick={() => { void (inboxApi as unknown as { openMedia: (rel: string) => Promise<unknown> }).openMedia(m.relPath); }}
+              style={{
+                width: 48,
+                height: 48,
+                objectFit: 'cover',
+                borderRadius: 4,
+                cursor: 'pointer',
+                border: '1px solid #e0e0e0'
+              }}
+            />
           ))}
         </div>
       )}

tests/unit/NoteCard.test.tsx

@@ -0,0 +1,81 @@
+// @vitest-environment jsdom
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import '@testing-library/jest-dom/vitest';
+import { render, screen, fireEvent, cleanup } from '@testing-library/react';
+import type { Note } from '@shared/types';
+
+const { mockOpenMedia } = vi.hoisted(() => ({
+  mockOpenMedia: vi.fn(async () => ({ ok: true }))
+}));
+
+vi.mock('../../src/renderer/inbox/api.js', () => ({
+  inboxApi: {
+    openMedia: mockOpenMedia,
+    deleteNote: vi.fn(),
+    restoreNote: vi.fn(),
+    permanentDeleteNote: vi.fn(),
+    updateAiFields: vi.fn(),
+    setDueDate: vi.fn(),
+    setIntent: vi.fn(),
+    dismissIntent: vi.fn()
+  }
+}));
+
+vi.mock('../../src/renderer/inbox/store.js', () => ({
+  useInbox: Object.assign(
+    () => ({}),
+    { getState: () => ({ setTagFilter: vi.fn() }) }
+  )
+}));
+
+import { NoteCard } from '../../src/renderer/inbox/components/NoteCard';
+
+const baseNote: Note = {
+  id: 'n1',
+  rawText: 'test',
+  aiTitle: 'T',
+  aiSummary: 'S',
+  aiStatus: 'done',
+  aiError: null,
+  aiProvider: null,
+  aiGeneratedAt: '2026-05-09T00:00:00Z',
+  titleEditedByUser: false,
+  summaryEditedByUser: false,
+  userIntent: null,
+  intentPromptedAt: '2026-05-09T00:00:00Z',
+  dueDate: null,
+  dueDateEditedByUser: false,
+  deletedAt: null,
+  lastRecalledAt: null,
+  recallDismissedAt: null,
+  createdAt: '2026-05-09T00:00:00Z',
+  updatedAt: '2026-05-09T00:00:00Z',
+  tags: [],
+  media: [
+    { id: 'm1', kind: 'image', relPath: 'media/n1/img1.png', mime: 'image/png', bytes: 100 },
+    { id: 'm2', kind: 'image', relPath: 'media/n1/img2.jpg', mime: 'image/jpeg', bytes: 200 }
+  ]
+};
+
+describe('NoteCard — image rendering', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    cleanup();
+  });
+
+  it('renders <img> for each media item', () => {
+    render(<NoteCard note={baseNote} onUpdated={() => {}} mode="inbox" />);
+    const imgs = screen.getAllByRole('presentation');
+    expect(imgs).toHaveLength(2);
+    expect(imgs[0]?.getAttribute('src')).toBe('inkling-media://media/n1/img1.png');
+    expect(imgs[1]?.getAttribute('src')).toBe('inkling-media://media/n1/img2.jpg');
+  });
+
+  it('clicking <img> calls inboxApi.openMedia', () => {
+    render(<NoteCard note={baseNote} onUpdated={() => {}} mode="inbox" />);
+    const first = screen.getAllByRole('presentation')[0];
+    if (first === undefined) throw new Error('expected at least one img');
+    fireEvent.click(first);
+    expect(mockOpenMedia).toHaveBeenCalledWith('media/n1/img1.png');
+  });
+});