Clean up UI code and improve agent hash display

- Remove unused imports and debug logging
- Change agent display from 'Agent Hash: full' to 'Agent: short8'
- Fix unused variable warnings

dashboard/src/ui/widgets/mod.rs

@@ -8,8 +8,6 @@ pub mod services;
 pub mod system;
 
 pub use backup::BackupWidget;
-pub use cpu::CpuWidget;
-pub use memory::MemoryWidget;
 pub use services::ServicesWidget;
 pub use system::SystemWidget;