add basic examples for database-wasm package

bindings/javascript/examples/database-wasm-vite/README.md

@@ -0,0 +1,63 @@
+# database-wasm-vite
+
+This is a minimal example showing how to use [`@tursodatabase/database-wasm`](https://www.npmjs.com/package/@tursodatabase/database-wasm) in the browser with [Vite](https://vite.dev/).  
+
+---
+
+## Usage
+
+```bash
+npm install
+npm run dev
+# or build assets and serve them with simple node.js server
+npm run build
+npm run serve
+```
+
+---
+
+## Important: COOP / COEP Headers
+
+Because `@tursodatabase/database-wasm` relies on **SharedArrayBuffer**, you need Cross-Origin headers in development and production:
+
+### Vite dev server config (`vite.config.js`)
+
+```js
+import { defineConfig } from 'vite'
+
+export default defineConfig({
+  server: {
+    headers: {
+      'Cross-Origin-Opener-Policy': 'same-origin',
+      'Cross-Origin-Embedder-Policy': 'require-corp',
+    }
+  }
+})
+```
+
+### Static production server (`server.mjs`)
+
+When serving the `dist/` build, also make sure your server sets these headers:
+
+```js
+res.setHeader("Cross-Origin-Opener-Policy", "same-origin");
+res.setHeader("Cross-Origin-Embedder-Policy", "require-corp");
+```
+
+### Vercel deployment
+
+If you deploy to [**Vercel**](https://vercel.com/), add a `vercel.json` file to ensure COOP / COEP headers are set:
+
+```json
+{
+  "headers": [
+    {
+      "source": "/(.*)",
+      "headers": [
+        { "key": "Cross-Origin-Opener-Policy", "value": "same-origin" },
+        { "key": "Cross-Origin-Embedder-Policy", "value": "require-corp" }
+      ]
+    }
+  ]
+}
+```