ci: add package test workflow

Author: Hweinstock

.github/workflows/package-test.yml

@@ -0,0 +1,20 @@
+name: Package Test
+
+on:
+  pull_request:
+    branches: [main]
+  workflow_call:
+
+jobs:
+  pack-install-verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-node@v6
+        with:
+          node-version: '20.x'
+      - run: npm ci
+      - run: npm run build
+      - run: npm pack
+      - run: npm install -g aws-agentcore-*.tgz
+      - run: agentcore --version