Add GitHub Actions workflow for running tests (via Claude dog fooding…

… run_script/run_command tools)

.github/workflows/tests.yml

@@ -0,0 +1,26 @@
+name: Tests
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Use Node.js 20.x
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20.x'
+        cache: 'npm'
+
+    - name: Install dependencies
+      run: npm ci
+
+    - name: Run tests
+      run: npm test