Migrate AA demo app from npm to pnpm (#3592)

* Replace npm lockfile with pnpm

* Update README to use pnpm

* Update demo setup script to use pnpm

* Remove redundant npm dependency ignore for aa-demo-app in dependabot configuration

Author: silva-fj

.github/dependabot.yml

@@ -55,11 +55,6 @@ updates:
     schedule:
       interval: "weekly"
 
-  # Explicitly ignore aa-demo-app dependencies
-  - package-ecosystem: "npm"
-    directory: "/tee-worker/omni-executor/aa-contracts/aa-demo-app"
-    open-pull-requests-limit: 0
-
   # GitHub Actions
   - package-ecosystem: github-actions
     directory: '/'

tee-worker/omni-executor/aa-contracts/aa-demo-app/README.md

@@ -25,7 +25,7 @@ This application demonstrates:
 
 ## Prerequisites
 
-- Node.js 18+ and npm
+- Node.js 18+ and pnpm
 - [Foundry](https://book.getfoundry.sh/getting-started/installation) installed
 - A web3 wallet (MetaMask or similar)
 - Git
@@ -82,10 +82,10 @@ This creates/updates the `.env.local` file in the demo app with the correct cont
 cd aa-demo-app
 
 # Install dependencies (first time only)
-npm install
+pnpm install
 
 # Start the development server
-npm run dev
+pnpm dev
 ```
 
 Open [http://localhost:3000](http://localhost:3000) in your browser.