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>

dashboard/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard"
-version = "0.1.208"
+version = "0.1.209"
 edition = "2021"
 
 [dependencies]

dashboard/src/ui/widgets/system.rs

@@ -26,7 +26,7 @@ pub struct SystemWidget {
     cpu_load_1min: Option<f32>,
     cpu_load_5min: Option<f32>,
     cpu_load_15min: Option<f32>,
-    cpu_cstate: Option<String>,
+    cpu_cstates: Vec<cm_dashboard_shared::CStateInfo>,
     cpu_status: Status,
     
     // Memory metrics
@@ -102,7 +102,7 @@ impl SystemWidget {
             cpu_load_1min: None,
             cpu_load_5min: None,
             cpu_load_15min: None,
-            cpu_cstate: None,
+            cpu_cstates: Vec::new(),
             cpu_status: Status::Unknown,
             memory_usage_percent: None,
             memory_used_gb: None,
@@ -137,12 +137,18 @@ impl SystemWidget {
         }
     }
 
-    /// Format CPU C-state (idle depth)
+    /// Format CPU C-states (idle depth) with percentages
     fn format_cpu_cstate(&self) -> String {
-        match &self.cpu_cstate {
-            Some(cstate) => cstate.clone(),
-            None => "—".to_string(),
+        if self.cpu_cstates.is_empty() {
+            return "—".to_string();
         }
+
+        // Format top 3 C-states with percentages: "C10:79% C8:10% C6:8%"
+        self.cpu_cstates
+            .iter()
+            .map(|cs| format!("{}:{:.0}%", cs.name, cs.percent))
+            .collect::<Vec<_>>()
+            .join(" ")
     }
 
     /// Format memory usage
@@ -188,7 +194,7 @@ impl Widget for SystemWidget {
         self.cpu_load_1min = Some(cpu.load_1min);
         self.cpu_load_5min = Some(cpu.load_5min);
         self.cpu_load_15min = Some(cpu.load_15min);
-        self.cpu_cstate = Some(cpu.cstate.clone());
+        self.cpu_cstates = cpu.cstates.clone();
         self.cpu_status = Status::Ok;
 
         // Extract memory data directly