add CI/CD workflows

.github/workflows/build.yml

@@ -0,0 +1,33 @@
+name: Build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: '1.25'
+
+      - name: Build
+        run: make build
+
+      - name: Test
+        run: make test
+
+      - name: Vet
+        run: make vet
+
+      - name: Format check
+        run: |
+          make fmt
+          git diff --exit-code