Migrate service control from ZMQ to SSH with real-time progress

Replace ZMQ-based service start/stop commands with SSH execution in tmux
popups. This provides better user feedback with real-time systemctl output
while eliminating blocking operations from the main message processing loop.

Changes:
- Service start/stop now use SSH with progress display
- Added backup functionality with 'B' key
- Preserved transitional icons (↑/↓) for immediate visual feedback
- Removed all ZMQ service control commands and handlers
- Updated configuration to include backup_alias setting
- All operations (rebuild, backup, services) now use consistent SSH interface

This ensures stable heartbeat processing while providing superior user
experience with live command output and service status feedback.

dashboard/src/ui/mod.rs

@@ -23,8 +23,6 @@ use widgets::{BackupWidget, ServicesWidget, SystemWidget, Widget};
 /// Commands that can be triggered from the UI
 #[derive(Debug, Clone)]
 pub enum UiCommand {
-    ServiceStart { hostname: String, service_name: String },
-    ServiceStop { hostname: String, service_name: String },
     TriggerBackup { hostname: String },
 }
 
@@ -272,20 +270,84 @@ impl TuiApp {
                             .ok(); // Ignore errors, tmux will handle them
                     }
                 }
+                KeyCode::Char('B') => {
+                    // Backup command - works on any panel for current host
+                    if let Some(hostname) = self.current_host.clone() {
+                        let connection_ip = self.get_connection_ip(&hostname);
+                        // Create command that shows logo, runs backup, and waits for user input
+                        let logo_and_backup = format!(
+                            "bash -c 'cat << \"EOF\"\nBackup Operation\nTarget: {} ({})\n\nEOF\nssh -tt {}@{} \"bash -ic {}\"\necho\necho \"========================================\"\necho \"Backup completed. Press any key to close...\"\necho \"========================================\"\nread -n 1 -s\nexit'",
+                            hostname,
+                            connection_ip,
+                            self.config.ssh.rebuild_user,
+                            connection_ip,
+                            self.config.ssh.backup_alias
+                        );
+                        
+                        std::process::Command::new("tmux")
+                            .arg("split-window")
+                            .arg("-v")
+                            .arg("-p")
+                            .arg("30")
+                            .arg(&logo_and_backup)
+                            .spawn()
+                            .ok(); // Ignore errors, tmux will handle them
+                    }
+                }
                 KeyCode::Char('s') => {
-                    // Service start command
+                    // Service start command via SSH with progress display
                     if let (Some(service_name), Some(hostname)) = (self.get_selected_service(), self.current_host.clone()) {
-                        if self.start_command(&hostname, CommandType::ServiceStart, service_name.clone()) {
-                            return Ok(Some(UiCommand::ServiceStart { hostname, service_name }));
-                        }
+                        // Start transition tracking for visual feedback
+                        self.start_command(&hostname, CommandType::ServiceStart, service_name.clone());
+                        
+                        let connection_ip = self.get_connection_ip(&hostname);
+                        let service_start_command = format!(
+                            "bash -c 'cat << \"EOF\"\nService Start: {}.service\nTarget: {} ({})\n\nEOF\nssh -tt {}@{} \"sudo systemctl start {}.service && echo \\\"Service started successfully\\\" && sudo systemctl status {}.service --no-pager -l\"\necho\necho \"========================================\"\necho \"Operation completed. Press any key to close...\"\necho \"========================================\"\nread -n 1 -s\nexit'",
+                            service_name,
+                            hostname,
+                            connection_ip,
+                            self.config.ssh.rebuild_user,
+                            connection_ip,
+                            service_name,
+                            service_name
+                        );
+                        
+                        std::process::Command::new("tmux")
+                            .arg("split-window")
+                            .arg("-v")
+                            .arg("-p")
+                            .arg("30")
+                            .arg(&service_start_command)
+                            .spawn()
+                            .ok(); // Ignore errors, tmux will handle them
                     }
                 }
                 KeyCode::Char('S') => {
-                    // Service stop command
+                    // Service stop command via SSH with progress display
                     if let (Some(service_name), Some(hostname)) = (self.get_selected_service(), self.current_host.clone()) {
-                        if self.start_command(&hostname, CommandType::ServiceStop, service_name.clone()) {
-                            return Ok(Some(UiCommand::ServiceStop { hostname, service_name }));
-                        }
+                        // Start transition tracking for visual feedback
+                        self.start_command(&hostname, CommandType::ServiceStop, service_name.clone());
+                        
+                        let connection_ip = self.get_connection_ip(&hostname);
+                        let service_stop_command = format!(
+                            "bash -c 'cat << \"EOF\"\nService Stop: {}.service\nTarget: {} ({})\n\nEOF\nssh -tt {}@{} \"sudo systemctl stop {}.service && echo \\\"Service stopped successfully\\\" && sudo systemctl status {}.service --no-pager -l\"\necho\necho \"========================================\"\necho \"Operation completed. Press any key to close...\"\necho \"========================================\"\nread -n 1 -s\nexit'",
+                            service_name,
+                            hostname,
+                            connection_ip,
+                            self.config.ssh.rebuild_user,
+                            connection_ip,
+                            service_name,
+                            service_name
+                        );
+                        
+                        std::process::Command::new("tmux")
+                            .arg("split-window")
+                            .arg("-v")
+                            .arg("-p")
+                            .arg("30")
+                            .arg(&service_stop_command)
+                            .spawn()
+                            .ok(); // Ignore errors, tmux will handle them
                     }
                 }
                 KeyCode::Char('J') => {