feat(ci): add GitHub Actions CI workflow with test, typecheck, and build jobs

Add CI that runs tests, typecheck, and build verification on push/PR to master.
Include test script in package.json and new .github/workflows/ci.yml.

Adds:
- .github/workflows/ci.yml: CI workflow with test, typecheck, and build jobs
- package.json: test script entry

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

.github/workflows/ci.yml

@@ -0,0 +1,69 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: bun install
+        env:
+          BUN_INSTALL_ALLOW_SCRIPTS: "@ast-grep/napi"
+
+      - name: Run tests
+        run: bun test
+
+  typecheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: bun install
+        env:
+          BUN_INSTALL_ALLOW_SCRIPTS: "@ast-grep/napi"
+
+      - name: Type check
+        run: bun run typecheck
+
+  build:
+    runs-on: ubuntu-latest
+    needs: [test, typecheck]
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: bun install
+        env:
+          BUN_INSTALL_ALLOW_SCRIPTS: "@ast-grep/napi"
+
+      - name: Build
+        run: bun run build
+
+      - name: Verify build output
+        run: |
+          test -f dist/index.js || (echo "ERROR: dist/index.js not found!" && exit 1)
+          test -f dist/index.d.ts || (echo "ERROR: dist/index.d.ts not found!" && exit 1)