ci: fail when the committed dist is stale

dist/ is shipped in the repo because git/package installs require the
compiled runtime; verify after build that it matches the sources.

Author: TheStreamCode

.github/workflows/ci.yml

@@ -25,5 +25,14 @@ jobs:
       - name: Build
         run: npm run build
 
+      - name: Verify committed dist matches the build
+        run: |
+          if [ -n "$(git status --porcelain dist)" ]; then
+            echo "dist/ is out of date with the TypeScript sources."
+            echo "Run 'npm run build' and commit the updated dist/."
+            git diff --stat dist
+            exit 1
+          fi
+
       - name: Unit tests
         run: npm test