ci: run tests on pull requests and pushes to main

publish.yml only triggers on version tag pushes, so a regression is
caught at publish time, not before. Add a CI workflow that runs npm
test on every PR and every push to main, mirroring the shape of
butterstack-connector's ci.yml.

Author: ryanlitalien

.github/workflows/ci.yml

@@ -0,0 +1,24 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  cli-node:
+    timeout-minutes: 10
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v7
+      - name: Set up Node
+        uses: actions/setup-node@v7
+        with:
+          node-version-file: '.nvmrc'
+      - name: Run tests
+        run: npm test