Angular Build Optimization: Budgets, Caching, and Versioning

A professional deployment is not just 'ng build'. It includes:
- caching strategy
- cache busting
- performance budgets

## Cache busting (Angular already helps)

Angular outputs hashed filenames like:
`main.8f3a2c.js`

That means you can cache JS for a long time safely.

## Recommended caching strategy

- HTML: short cache (or no-cache), because it changes and points to new bundles
- JS/CSS assets: long cache because filenames are hashed

## Budgets (prevent bundle bloat)

In `angular.json`, budgets can warn if bundles get too big.
This protects performance as the app grows.

## Versioning tip

Show app version in UI (footer or about page) so QA can verify deployments quickly.

> Next: Error handling at scale, global error handler and logging.