Show top 3 C-states with usage percentages

- Changed CpuData.cstate from String to Vec<CStateInfo>
- Added CStateInfo struct with name and percent fields
- Collector calculates percentage for each C-state based on accumulated time
- Sorts and returns top 3 C-states by usage
- Dashboard displays: "C10:79% C8:10% C6:8%"

Provides better visibility into CPU idle state distribution.

Bump version to v0.1.209

Co-Authored-By: Claude <noreply@anthropic.com>

agent/src/collectors/cpu.rs

@@ -119,30 +119,27 @@ impl CpuCollector {
         utils::parse_u64(content.trim())
     }
 
-    /// Collect CPU C-state (idle depth) and populate AgentData
+    /// Collect CPU C-state (idle depth) and populate AgentData with top 3 C-states by usage
     async fn collect_cstate(&self, agent_data: &mut AgentData) -> Result<(), CollectorError> {
         // Read C-state usage from first CPU (representative of overall system)
         // C-states indicate CPU idle depth: C1=light sleep, C6=deep sleep, C10=deepest
 
-        let mut deepest_state = String::from("C0"); // Default to active
-        let mut max_time: u64 = 0;
+        let mut cstate_times: Vec<(String, u64)> = Vec::new();
+        let mut total_time: u64 = 0;
 
-        // Check C-states from CPU0
+        // Collect all C-state times from CPU0
         for state_num in 0..=10 {
             let time_path = format!("/sys/devices/system/cpu/cpu0/cpuidle/state{}/time", state_num);
             let name_path = format!("/sys/devices/system/cpu/cpu0/cpuidle/state{}/name", state_num);
 
             if let Ok(time_str) = utils::read_proc_file(&time_path) {
                 if let Ok(time) = utils::parse_u64(time_str.trim()) {
-                    if time > max_time {
-                        // This state has most accumulated time
-                        if let Ok(name) = utils::read_proc_file(&name_path) {
-                            let state_name = name.trim().to_string();
-                            // Skip POLL state (not real idle)
-                            if state_name != "POLL" {
-                                max_time = time;
-                                deepest_state = state_name;
-                            }
+                    if let Ok(name) = utils::read_proc_file(&name_path) {
+                        let state_name = name.trim().to_string();
+                        // Skip POLL state (not real idle)
+                        if state_name != "POLL" && time > 0 {
+                            cstate_times.push((state_name, time));
+                            total_time += time;
                         }
                     }
                 }
@@ -152,7 +149,26 @@ impl CpuCollector {
             }
         }
 
-        agent_data.system.cpu.cstate = deepest_state;
+        // Sort by time descending to get top 3
+        cstate_times.sort_by(|a, b| b.1.cmp(&a.1));
+
+        // Calculate percentages for top 3 and populate AgentData
+        agent_data.system.cpu.cstates = cstate_times
+            .iter()
+            .take(3)
+            .map(|(name, time)| {
+                let percent = if total_time > 0 {
+                    (*time as f32 / total_time as f32) * 100.0
+                } else {
+                    0.0
+                };
+                cm_dashboard_shared::CStateInfo {
+                    name: name.clone(),
+                    percent,
+                }
+            })
+            .collect();
+
         Ok(())
     }
 }