CI: standard build/test pipeline (wave-1 rollout; node-free checkouts, job timeout)

.gitea/workflows/build.yml

@@ -0,0 +1,20 @@
+name: build
+on: [push, workflow_dispatch]
+
+jobs:
+  build-test:
+    runs-on: docker
+    container: node:20-bookworm
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        run: git clone --depth 1 ${{ github.server_url }}/${{ github.repository }}.git .
+
+      - name: Install
+        run: npm ci || npm install
+
+      - name: Build
+        run: npm run build --if-present
+
+      - name: Test
+        run: npm test --if-present