Update app store screenshots/copy to reflect new IA

[christabel888]

Context: Store-listing consistency with the new positioning -- not a code change.

Where:

• App store metadata / marketing assets (outside this repo's code, but tracked here since it's part of the pivot)

What to do:

• Update screenshots and store copy once the new dashboards (Scaffold NetworkDashboardScreen.tsx and useNetworkDashboardScreen.ts hook #21-Add largest transfers list and biometric gate to Wallet Dashboard screen #35) and nav (Restructure MainNavigator.tsx tabs: Overview, Assets, Wallets, Soroban, Rankings, Explorer #36) have shipped.

Suggested approach:

1. This is asset/copy work outside the codebase -- coordinate with whoever owns app store listings, and time it to land after Scaffold NetworkDashboardScreen.tsx and useNetworkDashboardScreen.ts hook #21-Update app store screenshots/copy to reflect new IA #41's screens are actually shippable, not before.

Watch out for:

• Store screenshots require review time on both app stores -- budget lead time before a planned release, this isn't a same-day change.

Definition of done:

• Store listing reflects the current app, not the pre-pivot explorer framing