feat(ai): ollama embed-text wrapper

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

tests/ai/ollama.test.js

@@ -0,0 +1,36 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { embedText, padTo, OllamaError } from '../../lib/ai/ollama.js';
+
+beforeEach(() => {
+  global.fetch = vi.fn(async () => new Response(
+    JSON.stringify({ embedding: new Array(768).fill(0.1) }),
+    { status: 200, headers: { 'content-type': 'application/json' }}
+  ));
+});
+afterEach(() => vi.restoreAllMocks());
+
+describe('ollama.embedText', () => {
+  it('returns 768-dim vector', async () => {
+    const v = await embedText('hello');
+    expect(v).toHaveLength(768);
+    expect(v[0]).toBeCloseTo(0.1, 5);
+  });
+
+  it('throws OllamaError on non-200', async () => {
+    global.fetch = vi.fn(async () => new Response('boom', { status: 502 }));
+    await expect(embedText('x')).rejects.toThrow(OllamaError);
+  });
+});
+
+describe('padTo', () => {
+  it('pads short vectors with zeros', () => {
+    const v = padTo([1, 2, 3], 5);
+    expect(v).toEqual([1, 2, 3, 0, 0]);
+  });
+  it('truncates long vectors', () => {
+    expect(padTo([1, 2, 3, 4, 5], 3)).toEqual([1, 2, 3]);
+  });
+  it('returns same on exact length', () => {
+    expect(padTo([1, 2], 2)).toEqual([1, 2]);
+  });
+});