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/collectors/disk.rs

@@ -1,7 +1,7 @@
 use anyhow::Result;
 use async_trait::async_trait;
 use cm_dashboard_shared::{Metric, MetricValue, Status};
-use std::collections::HashMap;
+
 use std::process::Command;
 use std::time::Instant;
 use tracing::debug;
@@ -398,7 +398,7 @@ impl Collector for DiskCollector {
                 }
 
                 // Add SMART health metrics for each unique physical device
-                for (physical_device, disks) in physical_devices {
+                for (physical_device, _disks) in physical_devices {
                     let (health_status, temperature) = self.get_smart_health(&physical_device);
                     let device_name = physical_device.strip_prefix("/dev/").unwrap_or(&physical_device);
                     let timestamp = chrono::Utc::now().timestamp() as u64;