Add WebView wallet compatibility for Solana SDK

- Add Buffer polyfill (from, alloc, concat, isBuffer) for Solana SDK
- Add full BN-like _bn object with negative, words, toArray methods
- Add toBuffer, toBytes, equals methods to publicKey object
- Fix "x.pubkey.equals is not a function" error in deposit flow
- Fix "Cannot read properties of undefined (reading 'negative')" error
- Remove verbose token debug logging
- Update default browser URL to vero.x1.xyz

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Jack Levin