feat: EVM support alongside Solana

[piotrostr]

This PR adds Ethereum Virtual Machine (EVM) support and enhances the backend interoperability by allowing different chain-specific agents to handle user requests. Key changes include:

Core Changes:

• Added wagmi and viem dependencies for EVM integration
• Implemented parallel Solana and EVM wallet delegation flow
• Created chain-specific agents (Solana, EVM, Pump) with dedicated tools
• Modified backend port to 6969 for consistency
• Enhanced portfolio view to display both SOL and ETH balances

Frontend Updates:

• Updated chat selector to handle EVM interactions
• Modified wallet connection flow to require both Solana and EVM delegation
• Enhanced portfolio display to show chain-specific wallet addresses
• Added chain parameter to backend requests for proper routing

Backend Improvements:

• Restructured server to support multiple chain-specific agents
• Added EVM tools for basic operations (transfers, swaps, approvals)
• Enhanced error handling for chain-specific operations
• Implemented proper agent selection based on chat type