bug: usdt activity detail and more details open without screen transitions #1598

Refs:

• fix: stabilize usdt wallet and payment layouts #1565

What happened?

Opening a USDT activity from the USDT wallet swaps the detail screen in with no transition, and going back swaps it out the same way. Inside the detail, "More details" doesn't open a new screen with a transition either: the technical details just appear in place. Savings and Spending activities open their detail and more-details screens with the regular slide.

UsdtWalletScreen shows UsdtActivityDetail through an if (selectedTransfer != null) state swap rather than a navigation destination, and UsdtActivityDetail toggles showDetails in place. #1565 only adds an opaque background to these screens, not the transitions.

Expected behavior

USDT activity detail and its "More details" screen open and close with the same slide transitions as the Savings and Spending activity screens.

Steps to Reproduce

1. Enable USDT and open the USDT wallet.
2. Tap an activity, then go back.
3. Open an activity and tap "More details".
4. Compare with a Savings or Spending activity and its details.

Bitkit Version

3.0.0 (Play Store, mainnet)

Device / OS

Pixel 10 Pro

Reproducibility

Always