Add CI workflow to validate builds on PRs

Runs npm build and TypeScript type-checking on every pull request
and push to main. Use as a required status check in branch protection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: gui-uxdoccom

.github/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+      - run: npm ci
+      - run: npm run build
+      - run: npx tsc --noEmit -p tsconfig.plugin.json
+      - run: npx tsc --noEmit -p tsconfig.json