ci: GitHub Actions 워크플로우 추가

Node.js lint + build 자동화 (push/PR on main)

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

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci --legacy-peer-deps
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Build
+        run: npm run build
+        env:
+          VITE_API_BASE_URL: https://a301.api.tolelom.xyz