[Mobile] Research native Android version of Zap Browser

[shadowbipnode]

Research and plan a native Android version of Zap Browser.

Goals:

• evaluate Android browser architecture options
• evaluate Chromium WebView vs GeckoView
• preserve Lightning/Cashu/Nostr workflows on mobile
• native NIP-07 support on Android
• mobile NWC integration
• secure local key storage
• Android permission model review
• mobile privacy protections
• synchronization strategy review (optional/local-first only)

Important:
The Android version should not become a generic mobile browser clone. The focus should remain sovereign Lightning, Cashu and Nostr workflows with privacy-first architecture.

Potential future goals:

• mobile signer mode
• mobile companion mode
• QR/NFC workflows
• LNURL mobile UX
• Android share-sheet integration
• external wallet interoperability