Global Error Handling and Logging (Production Ready)

In production apps, you want visibility:
- which errors happened
- how often
- on which page
- which browser

Angular allows a global error handler.

## Example: custom ErrorHandler

```ts
import { ErrorHandler, Injectable } from '@angular/core';

@Injectable()
export class GlobalErrorHandler implements ErrorHandler {
  handleError(error: any) {
    console.error('Global error:', error);

    // Example: send to logging API
    // fetch('/api/log', { method: 'POST', body: JSON.stringify({ error }) });
  }
}
```

## Provide it

```ts
bootstrapApplication(AppComponent, {
  providers: [
    { provide: ErrorHandler, useClass: GlobalErrorHandler },
  ],
});
```

## Best practice

- log errors with context (route, user id if safe, timestamp)
- avoid logging sensitive data
- show user-friendly fallback UI instead of raw error messages

> Next: Guards vs resolvers vs interceptors, when to use which (architecture clarity).