Upgrade Belt CLI to use Expo 56

[rakeshpetit]

Upgrade the Belt CLI to Expo SDK 56. This PR uses the upgrading-expo skill and was authored using Claude code.

Changes

app.json

• Removed deprecated splash config key
• Expanded plugins to configure splash screen via expo-splash-screen plugin (SDK 56 requirement)

tsconfig.json

• Removed baseUrl, added "types": ["jest"]
• Updated path aliases to use ./ prefix

How to test

Tested a builds/TestApp which now runs on Expo 56

Checkout this branch and run the commands below:

// clear existing builds and belt build
rm -rf dist builds
// Generate Belt CLI build
yarn build 
// Generate new ExpoSample app using the Belt CLI
node bin/checks/build-with-latest-expo.check.js