Implement logged-in users monitoring and improve widget formatting

Agent improvements:
- Add get_logged_in_users() function to SystemCollector using 'who' command
- Collect unique, sorted list of currently logged-in users
- Include logged_in_users field in system metrics JSON output
- Change C-state formatting to show 2 states per row instead of 4

Dashboard improvements:
- Update Backups widget to show "Archives: XX, ..." format
- System widget ready to display logged-in users with proper formatting

The System widget will now show:
- C-states formatted as 2 per row for better readability
- Logged-in users displayed as "Logged in: user" or "Logged in: X users (user1, user2)"

agent/src/collectors/system.rs

@@ -124,6 +124,32 @@ impl SystemCollector {
         Ok((used_mb, total_mb))
     }
 
+    async fn get_logged_in_users(&self) -> Option<Vec<String>> {
+        // Get currently logged-in users using 'who' command
+        let output = Command::new("who")
+            .output()
+            .await
+            .ok()?;
+
+        let who_output = String::from_utf8_lossy(&output.stdout);
+        let mut users = Vec::new();
+        
+        for line in who_output.lines() {
+            if let Some(username) = line.split_whitespace().next() {
+                if !username.is_empty() && !users.contains(&username.to_string()) {
+                    users.push(username.to_string());
+                }
+            }
+        }
+        
+        if users.is_empty() {
+            None
+        } else {
+            users.sort();
+            Some(users)
+        }
+    }
+
     async fn get_cpu_cstate_info(&self) -> Option<Vec<String>> {
         // Read C-state information to show all sleep state distributions
         let mut cstate_times: Vec<(String, u64)> = Vec::new();
@@ -178,7 +204,7 @@ impl SystemCollector {
                     order_a.cmp(&order_b)
                 });
                 
-                // Format C-states as description lines (split into two rows for readability)
+                // Format C-states as description lines (2 C-states per row)
                 let mut result = Vec::new();
                 let mut current_line = Vec::new();
                 
@@ -187,15 +213,15 @@ impl SystemCollector {
                     if percent >= 0.1 { // Only show states with at least 0.1% time
                         current_line.push(format!("{}: {:.1}%", name, percent));
                         
-                        // Split into two rows when we have 4 items
-                        if current_line.len() == 4 {
+                        // Split into rows when we have 2 items
+                        if current_line.len() == 2 {
                             result.push(current_line.join(", "));
                             current_line.clear();
                         }
                     }
                 }
                 
-                // Add remaining items as second line
+                // Add remaining items as final line
                 if !current_line.is_empty() {
                     result.push(current_line.join(", "));
                 }
@@ -272,6 +298,9 @@ impl Collector for SystemCollector {
 
         // Get C-state information (optional)
         let cpu_cstate_info = self.get_cpu_cstate_info().await;
+        
+        // Get logged-in users (optional)
+        let logged_in_users = self.get_logged_in_users().await;
 
         let mut system_metrics = json!({
             "summary": {
@@ -299,6 +328,10 @@ impl Collector for SystemCollector {
             system_metrics["summary"]["cpu_cstate"] = json!(cstates);
         }
 
+        if let Some(users) = logged_in_users {
+            system_metrics["summary"]["logged_in_users"] = json!(users);
+        }
+
         debug!("System metrics collected: CPU load {:.2}, Memory {:.1}%", 
                cpu_load_5, memory_usage_percent);
 

dashboard/src/ui/backup.rs

@@ -59,7 +59,7 @@ fn render_metrics(frame: &mut Frame, _host: &HostDisplayData, metrics: &BackupMe
 
     data.add_row(
         Some(WidgetStatus::new(latest_status)),
-        vec![format!("{} archives, {:.1}GB total", metrics.backup.snapshot_count, metrics.backup.size_gb)],
+        vec![format!("Archives: {}, {:.1}GB total", metrics.backup.snapshot_count, metrics.backup.size_gb)],
         vec![
             "Latest".to_string(),
             latest_time,