feat: Implement Display User Balance after connecting

[wheval]

🚀 Pull Request

📝 Description

• This PR closes Display User Balance Using starknet-react After Wallet Connect #56
• Created useTokenBalance hook for fetching ETH balance using ERC20 ABI with 30-second polling
• Enhanced AddressBar component to display balance in compact button and expanded modal views
• Added comprehensive dark mode support with dark: classes for all AddressBar elements
• Fixed chain ID format from numeric to hex values for Cartridge Controller compatibility
• Separated chain configs: BigInt IDs for starknet-react, hex IDs for Cartridge Controller
• Fixed BigInt arithmetic error by changing multiplication to bit shifting operation
• Added network-aware account detection using provider.getClassHashAt() instead of account method
• Created utils/networkUtils.ts with network helper functions for info, names, and explorer URLs
• Added network status indicators with green dot for mainnet and blue dot for testnet
• Implemented dynamic deployment status messages based on current network and account status
• Simplified network configuration to single constant NETWORK: "sepolia" | "mainnet"
• Added defaultChainId prop to StarknetConfig to respect NETWORK constant setting
• Fixed StarknetProvider SSR error with lazy ControllerConnector initialization using window check
• Fixed TotalTransactionChart SSR error by replacing direct window.innerWidth with React state
• Fixed PaymentModal TypeScript error by adding proper null checks for user variable
• Updated useEffect dependencies from chain to chain?.id to prevent size change errors

🔄 Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• UI/UX improvement
• Performance optimization
• Code refactor
• Documentation update
• Test coverage
• CI/CD improvement
• Other (please describe):

🧪 How Has This Been Tested?

• Unit tests
• Integration tests
• Manual testing
• Accessibility testing
• Cross-browser testing

📸 Screenshots

📋 Checklist

• My code follows the project's coding style
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes
• Any dependent changes have been merged and published

📚 Additional Context

🔗 Related Issues