Add test script and CI workflow

- Add top-level test script that runs tests across all workspaces
- Add GitHub Actions workflow to run tests on PRs and merges to master

Co-authored-by: Ona <no-reply@ona.com>

.github/workflows/test.yml

@@ -0,0 +1,24 @@
+name: Test
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Run tests
+        run: bun test