fix: replace log.Fatal with proper error handling

[virajbhartiya]

Summary

Replaces excessive use of log.Fatal() with proper error handling across multiple files to improve application reliability and user experience.

Changes

• Replace log.Fatal() calls with log.Error() and proper error returns
• Implement graceful error handling in storage commands
• Add error propagation in balance and stake operations
• Improve error handling in client operations

Files Modified

• internal/commands/storage.go
• cmd/cli/balance.go
• cmd/cli/stake.go
• cmd/cli/client.go

Impact

• Prevents application termination on non-critical errors
• Enables better error recovery and user feedback
• Follows Go best practices for error handling
• Improves overall application stability