Add missing npm ci before npx wrangler deploy

Otherwise this fails:

```console
src/index.ts:3:32 - error TS2307: Cannot find module '@cloudflare/playwright-mcp' or its corresponding type declarations.

3 import { createMcpAgent } from '@cloudflare/playwright-mcp';
```

Author: ericclemmons

README.md

@@ -25,6 +25,7 @@ npm run build
 
 ```bash
 cd cloudflare/example
+npm ci
 npx wrangler deploy
 ```