Add GitHub workflow for PRs to lint and run create-data

Uses `npm ci --ignore-scripts` for clean installs and prevent
create-data running implicitly in postinstall.

Author: mikejamesthompson

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  lint-and-create-data:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version-file: '.nvmrc'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci --ignore-scripts
+
+      - name: Run lint
+        run: npm run lint
+
+      - name: Run create-data
+        run: npm run create-data