Feature Request: use the app overlay to display goose progress

When goose makes progress on a task, updates are given through toasts. This is highly limited and not very helpful.

Instead we should make a custom compose view that shows up and shows what goose is thinking or doing and disappears after a reasonable time.

This might be especially handy if we need to get the users attention on a biometrics screen to ask them to authenticate or something like that.

Look for existing toast or overlay UI components in the codebase, likely in SwiftUI or UIKit views. The feature involves creating a custom compose view that appears and disappears automatically. Check how goose task progress is currently communicated and where biometrics authentication screens are handled. Testing will require simulating task progress and user interactions.

索引モデルが issue の本文から書いたものです。