Add CI workflow

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4
+        name: Install pnpm
+        with:
+          version: 9
+          run_install: false
+
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - name: Run type checking
+        run: pnpm typecheck
+
+      - name: Run Biome lint
+        run: pnpm biome check .
+
+      - name: Run tests
+        run: pnpm test

package.json

@@ -9,6 +9,7 @@
     "build": "tsc",
     "test": "vitest",
     "lint": "biome lint --write ./src",
+    "typecheck": "tsc --noEmit",
     "format": "biome format --write ./src",
     "prepare": "pnpm run build"
   },