feat(dashboard): dashboard_layout table + repo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/repos/dashboard_layout.test.js

@@ -0,0 +1,27 @@
+import { describe, it, expect, beforeAll } from 'vitest';
+import { resetDb } from '../helpers/db.js';
+import { migrateUp } from '../../lib/db/migrate.js';
+import * as repo from '../../lib/db/repos/dashboard_layout.js';
+
+beforeAll(async () => { await resetDb(); await migrateUp(); });
+
+describe('dashboard_layout repo', () => {
+  it('returns defaults when unset', async () => {
+    const l = await repo.get();
+    expect(l).toEqual({ card_order: [], hidden: [], sizes: {} });
+  });
+
+  it('upserts and reads back', async () => {
+    await repo.put({ card_order: ['clock', 'weather'], hidden: ['jobs'], sizes: { weather: 's' } });
+    const l = await repo.get();
+    expect(l.card_order).toEqual(['clock', 'weather']);
+    expect(l.hidden).toEqual(['jobs']);
+    expect(l.sizes).toEqual({ weather: 's' });
+  });
+
+  it('second put overwrites the same single row', async () => {
+    await repo.put({ card_order: ['host-perf'], hidden: [], sizes: {} });
+    const l = await repo.get();
+    expect(l.card_order).toEqual(['host-perf']);
+  });
+});