v1.0.26 — Amber login fix

- Fixed Amber (NIP-55) login: the callback URL was broken for HashRouter apps, causing login to silently fail. Amber now correctly returns to the app and completes login after user approval.
- Fixed race condition where two handlers competed to process the Amber callback result.
- After Amber login, app now returns you to the page you came from instead of always going to the home screen.