feat(jobs): embed.text worker (Ollama → vector(1024))

Pads nomic-embed-text's 768 dims to 1024 zeros so a later 1024-dim model
swap is a re-embed, not a migration (per master spec).

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

tests/jobs/workers/embed.test.js

@@ -0,0 +1,53 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { resetDb } from '../../helpers/db.js';
+import { migrateUp } from '../../../lib/db/migrate.js';
+import { stopBoss, waitForJob } from '../../helpers/boss.js';
+import { pool } from '../../../lib/db/pool.js';
+import * as queue from '../../../lib/jobs/queue.js';
+import { registerWorkers } from '../../../lib/jobs/index.js';
+import * as spaces from '../../../lib/db/repos/spaces.js';
+import * as pages from '../../../lib/db/repos/pages.js';
+
+beforeEach(async () => {
+  await resetDb(); await migrateUp(); await queue.start(); await registerWorkers();
+  global.fetch = vi.fn(async () => new Response(
+    JSON.stringify({ embedding: new Array(768).fill(0.42) }),
+    { status: 200, headers: { 'content-type': 'application/json' }}
+  ));
+});
+afterEach(async () => { await stopBoss(); vi.restoreAllMocks(); });
+
+describe('embed.text worker', () => {
+  it('writes a vector(1024) to the page row', async () => {
+    const sp = await spaces.create({ slug: 'e', name: 'E' }, { kind: 'user', id: null });
+    const pg = await pages.create(
+      { space_id: sp.id, slug: 'p', title: 'P', body_md: 'body' },
+      { kind: 'user', id: null }
+    );
+    const id = await queue.enqueue('embed.text', { entity_type: 'page', entity_id: pg.id });
+    const j = await waitForJob('embed.text', id, { timeoutMs: 10_000 });
+    expect(j.state).toBe('completed');
+    const { rows: [row] } = await pool.query(
+      'SELECT embedding::text AS embedding FROM pages WHERE id=$1', [pg.id]
+    );
+    expect(row.embedding).toBeTruthy();
+    // 1024 floats → at least 1023 commas in the literal
+    const commas = (row.embedding.match(/,/g) || []).length;
+    expect(commas).toBe(1023);
+  });
+
+  it('emits an audit log entry', async () => {
+    const sp = await spaces.create({ slug: 'e2', name: 'E2' }, { kind: 'user', id: null });
+    const pg = await pages.create(
+      { space_id: sp.id, slug: 'p', title: 'P', body_md: 'body' },
+      { kind: 'user', id: null }
+    );
+    const id = await queue.enqueue('embed.text', { entity_type: 'page', entity_id: pg.id });
+    await waitForJob('embed.text', id, { timeoutMs: 10_000 });
+    const { rows } = await pool.query(
+      `SELECT * FROM audit_log WHERE entity_type='page' AND entity_id=$1 AND actor_kind='worker'`,
+      [pg.id]
+    );
+    expect(rows.length).toBeGreaterThan(0);
+  });
+});