Integrate Solana wallet

Add Solana wallet integration using wallet-adapter: - Create WalletProvider wrapper and WalletInfo components - Wrap App with WalletContextProvider - Add WalletButton UI and wallet state displays on Home/Profile - Update Home/Profile to support wallet connection status and display - Prepare UI elements for Solana-based transactions (stablecoins) and address handling X-Lovable-Edit-ID: edt-01e9f20e-d978-412b-b9de-124b88651644