feat(karakeep): bookmark fetch client

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/karakeep/client.test.js

@@ -0,0 +1,35 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { getBookmark } from '../../lib/karakeep/client.js';
+
+let lastInit;
+beforeEach(() => {
+  lastInit = null;
+  global.fetch = vi.fn(async (url, init) => {
+    lastInit = init;
+    return new Response(
+      JSON.stringify({ id: 'b-1', url: 'https://example.com', title: 'X', tags: [{ name: 'archive' }] }),
+      { status: 200, headers: { 'content-type': 'application/json' }}
+    );
+  });
+});
+afterEach(() => { vi.restoreAllMocks(); });
+
+describe('karakeep client', () => {
+  it('fetches a bookmark with bearer token', async () => {
+    process.env.KARAKEEP_API_URL = 'https://karakeep.test';
+    process.env.KARAKEEP_API_TOKEN = 'tok-123';
+    const bm = await getBookmark('b-1');
+    expect(bm.url).toBe('https://example.com');
+    expect(lastInit.headers.Authorization).toBe('Bearer tok-123');
+  });
+
+  it('returns null on 404', async () => {
+    global.fetch = vi.fn(async () => new Response('', { status: 404 }));
+    expect(await getBookmark('nope')).toBeNull();
+  });
+
+  it('throws on other non-2xx', async () => {
+    global.fetch = vi.fn(async () => new Response('boom', { status: 503 }));
+    await expect(getBookmark('x')).rejects.toThrow();
+  });
+});