Remove service restart functionality and make R always rebuild host

Simplified keyboard controls by removing service restart functionality:

- Removed 'r' key restart functionality from Services panel
- Made 'R' key always trigger system rebuild regardless of focused panel
- Updated context shortcuts to show 'R: Rebuild Host' globally
- Removed all ServiceRestart enum variants and associated code:
  - UiCommand::ServiceRestart
  - CommandType::ServiceRestart
  - ServiceAction::Restart
- Cleaned up pending transition logic to only handle Start/Stop commands

The 'R' key now consistently rebuilds the current host from any panel,
while 's' and 'S' continue to handle service start/stop in Services panel.

agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-agent"
-version = "0.1.29"
+version = "0.1.30"
 edition = "2021"
 
 [dependencies]

agent/src/agent.rs

@@ -274,7 +274,6 @@ impl Agent {
         let action_str = match action {
             ServiceAction::Start => "start",
             ServiceAction::Stop => "stop", 
-            ServiceAction::Restart => "restart",
             ServiceAction::Status => "status",
         };
 
@@ -299,7 +298,7 @@ impl Agent {
         }
 
         // Force refresh metrics after service control to update service status
-        if matches!(action, ServiceAction::Start | ServiceAction::Stop | ServiceAction::Restart) {
+        if matches!(action, ServiceAction::Start | ServiceAction::Stop) {
             info!("Triggering immediate metric refresh after service control");
             if let Err(e) = self.collect_metrics_only().await {
                 error!("Failed to refresh metrics after service control: {}", e);

agent/src/communication/mod.rs

@@ -112,6 +112,5 @@ pub enum AgentCommand {
 pub enum ServiceAction {
     Start,
     Stop,
-    Restart,
     Status,
 }