[puter] add CI workflow for building frontend

Author: velzie

.github/workflows/main.yml

@@ -72,6 +72,52 @@ jobs:
             dist/*.js
             dist/*.js.map
             dist/*.wasm
+  frontend:
+    name: Build Frontend
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: latest
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - name: Get artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: scramjet
+
+      - name: Build Dreamland
+        run: |
+          cd dreamland
+          pnpm build
+
+      - name: Build Chobitsu
+        run: |
+          cd chobitsu
+          pnpm webpack build --mode development
+
+      - name: Build chobitsu_inject
+        run: |
+          cd chobitsu_inject
+          npx rollup -c
+
+      - name: Build Frontend
+        run: |
+          cd frontend
+          pnpm build
   tests:
     name: Run Scramjet Tests
     runs-on: ubuntu-latest