Improve dashboard UI layout and status aggregation

- Move hosts panel to left side above system panel
- Add dynamic column layout for hosts based on available width
- Fix status aggregation to properly calculate host status from widgets
- Align service panel columns with header
- Use blue color for metrics without status indicators
- Add offline host popup overlay
- Use foreground color for panel titles

dashboard/src/ui/widgets/system.rs

@@ -178,6 +178,36 @@ impl SystemWidget {
     pub fn get_kernel_version(&self) -> Option<String> {
         self.kernel_version.clone()
     }
+
+    /// Get overall status by aggregating all component statuses
+    pub fn get_overall_status(&self) -> Status {
+        if !self.has_data {
+            return Status::Offline;
+        }
+
+        let mut statuses = vec![self.cpu_status, self.memory_status, self.backup_status];
+
+        // Add storage pool and drive statuses
+        for pool in &self.storage_pools {
+            statuses.push(pool.status);
+            for drive in &pool.drives {
+                statuses.push(drive.status);
+            }
+            for drive in &pool.data_drives {
+                statuses.push(drive.status);
+            }
+            for drive in &pool.parity_drives {
+                statuses.push(drive.status);
+            }
+        }
+
+        // Add backup repository statuses
+        for repo in &self.backup_repositories {
+            statuses.push(repo.status);
+        }
+
+        Status::aggregate(&statuses)
+    }
 }
 
 use super::Widget;