ci: add build workflow

Author: harvenstar

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build

AGENTS.md

@@ -118,6 +118,8 @@ Read `docs/dev-rules.md` before writing any code. Key rules:
 - Long-poll `/wait` endpoint for agent integration
 - Keyboard shortcuts: `Escape` closes dropdown, `Cmd+Enter` submits
 - End-to-end tested with OpenClaw (Docker) via Feishu — full loop verified
+- Production single-port serving (`npm run build && npm start`)
+- Minimal CI build workflow (GitHub Actions: `npm ci && npm run build`)
 
 **Pending:**
 - npm global package (`openclaw-ui` on npm)