chore: add mod.ts file and update GitHub Actions workflow to use Node.js and pnpm

.github/workflows/jsr-publish.yml

@@ -14,10 +14,22 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: oven-sh/setup-bun@v2
+      
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v2
+        with:
+          version: latest
+
       - name: Install dependencies
-        run: bun install
+        run: pnpm install
+
       - name: Build
-        run: bun run build
+        run: pnpm build
+
       - name: Publish package
         run: npx jsr publish