Clean up unused imports and fix build warnings

- Remove unused imports (Duration, HashMap, SharedError, DateTime, etc.)
- Fix unused variables by prefixing with underscore
- Remove redundant dashboard.toml config file
- Update theme imports to use only needed components
- Maintain all functionality while reducing warnings
- Add srv02 to predefined hosts configuration
- Remove unused broadcast_command methods

agent/src/communication/mod.rs

@@ -1,6 +1,6 @@
 use anyhow::Result;
 use cm_dashboard_shared::{MetricMessage, MessageEnvelope};
-use tracing::{info, error, debug};
+use tracing::{info, debug};
 use zmq::{Context, Socket, SocketType};
 
 use crate::config::ZmqConfig;