feat: add conversation image previews and sharing

tests/media-library-exchange.test.ts

@@ -81,6 +81,54 @@ describe('MediaLibraryExchangeService', () => {
     expect(chat.sendChatImage).toHaveBeenCalledOnce();
     db.close();
   });
+
+  it('lists eligible choices and sends only the operator-selected matching asset', async () => {
+    const db = createTestDb();
+    const repository = new MediaLibraryRepository(db);
+    await addAsset(repository, directory, 'selfie-one', ['selfie'], 'sfw', 1);
+    await addAsset(repository, directory, 'selfie-two', ['selfie'], 'sfw', 2);
+    await addAsset(repository, directory, 'topless', ['topless'], 'nsfw', 3);
+    const chat = {
+      sendChatImage: vi.fn().mockResolvedValue({ eventId: '$selected', mxcUri: 'mxc://selected' }),
+      sendChatMessage: vi.fn().mockResolvedValue(true),
+    };
+    const service = new MediaLibraryExchangeService(repository, chat, logger(), 'account', directory);
+
+    expect(service.listShareable('room', 'send a selfie').assets.map((asset) => asset.id)).toEqual([
+      'selfie-two', 'selfie-one',
+    ]);
+    expect(await service.handleSelected('room', '$request', 'send a selfie', 'topless')).toMatchObject({
+      kind: 'human-required',
+    });
+    expect(await service.handleSelected('room', '$request', 'send a selfie', 'selfie-one')).toMatchObject({
+      kind: 'sent', assetId: 'selfie-one', requestKind: 'selfie',
+    });
+    expect(chat.sendChatImage).toHaveBeenCalledWith(
+      'room', expect.objectContaining({ fileName: 'selfie-one.jpg' }), expect.any(String), null,
+    );
+    db.close();
+  });
+
+  it('keeps an image-only partial delivery human-required on later attempts', async () => {
+    const db = createTestDb();
+    const repository = new MediaLibraryRepository(db);
+    await addAsset(repository, directory, 'selfie', ['selfie'], 'sfw', 1);
+    const chat = {
+      sendChatImage: vi.fn().mockResolvedValue({ eventId: '$image', mxcUri: 'mxc://image' }),
+      sendChatMessage: vi.fn().mockResolvedValue(false),
+    };
+    const service = new MediaLibraryExchangeService(repository, chat, logger(), 'account', directory);
+
+    await expect(service.handleSelected('room', '$request', 'send a selfie', 'selfie')).resolves.toMatchObject({
+      kind: 'human-required', remoteSent: true,
+    });
+    await expect(service.handleSelected('room', '$request', 'send a selfie', 'selfie')).resolves.toMatchObject({
+      kind: 'human-required', remoteSent: true,
+    });
+    expect(chat.sendChatImage).toHaveBeenCalledOnce();
+    expect(chat.sendChatMessage).toHaveBeenCalledOnce();
+    db.close();
+  });
 });
 
 async function addAsset(