Implement immediate transitional service icons with pending state tracking

- Replace timeout-based command status with pending service transitions
- Show immediate directional arrows when pressing service commands (↑ ↓ ↻)
- Track original service status and command type for each pending operation
- Automatically clear transitional icons when real status updates arrive
- Remove unused TerminalPopup and CommandStatus infrastructure
- Simplify visual feedback system using state-based approach

Service commands now provide instant visual feedback that persists until
the actual service state changes, eliminating timing issues and improving UX.

dashboard/src/ui/mod.rs

@@ -7,7 +7,7 @@ use ratatui::{
     Frame,
 };
 use std::collections::HashMap;
-use std::time::{Duration, Instant};
+use std::time::Instant;
 use tracing::info;
 
 pub mod theme;
@@ -28,12 +28,6 @@ pub enum UiCommand {
     TriggerBackup { hostname: String },
 }
 
-/// Command execution status for visual feedback
-#[derive(Debug, Clone)]
-pub enum CommandStatus {
-    /// Command is executing
-    InProgress { command_type: CommandType, target: String, start_time: std::time::Instant },
-}
 
 /// Types of commands for status tracking
 #[derive(Debug, Clone)]
@@ -70,8 +64,8 @@ pub struct HostWidgets {
     pub backup_scroll_offset: usize,
     /// Last update time for this host
     pub last_update: Option<Instant>,
-    /// Active command status for visual feedback
-    pub command_status: Option<CommandStatus>,
+    /// Pending service transitions for immediate visual feedback
+    pub pending_service_transitions: HashMap<String, (CommandType, String)>, // service_name -> (command_type, original_status)
 }
 
 impl HostWidgets {
@@ -84,7 +78,7 @@ impl HostWidgets {
             services_scroll_offset: 0,
             backup_scroll_offset: 0,
             last_update: None,
-            command_status: None,
+            pending_service_transitions: HashMap::new(),
         }
     }
 }
@@ -133,8 +127,6 @@ impl TuiApp {
 
     /// Update widgets with metrics from store (only for current host)
     pub fn update_metrics(&mut self, metric_store: &MetricStore) {
-        // Check for command timeouts first
-        self.check_command_timeouts();
         
         // Check for rebuild completion by agent hash change
         
@@ -168,6 +160,9 @@ impl TuiApp {
                     .copied()
                     .collect();
 
+                // Clear completed transitions first
+                self.clear_completed_transitions(&hostname, &service_metrics);
+
                 // Now get host widgets and update them
                 let host_widgets = self.get_or_create_host_widgets(&hostname);
 
@@ -209,9 +204,9 @@ impl TuiApp {
         // Sort hosts alphabetically
         let mut sorted_hosts = hosts.clone();
         
-        // Keep hosts that have ongoing commands even if they're offline
+        // Keep hosts that have pending transitions even if they're offline
         for (hostname, host_widgets) in &self.host_widgets {
-            if let Some(CommandStatus::InProgress { .. }) = &host_widgets.command_status {
+            if !host_widgets.pending_service_transitions.is_empty() {
                 if !sorted_hosts.contains(hostname) {
                     sorted_hosts.push(hostname.clone());
                 }
@@ -427,7 +422,7 @@ impl TuiApp {
         None
     }
 
-    /// Start command execution and track status for visual feedback (with state validation)
+    /// Start command execution with immediate visual feedback 
     pub fn start_command(&mut self, hostname: &str, command_type: CommandType, target: String) -> bool {
         // Get current service status to validate command
         let current_status = self.get_current_service_status(hostname, &target);
@@ -438,13 +433,11 @@ impl TuiApp {
             (CommandType::ServiceStop, Some("active")) => true,
             (CommandType::ServiceRestart, Some("active") | Some("inactive") | Some("failed") | Some("dead")) => true,
             (CommandType::ServiceStart, Some("active")) => {
-                // Already running - show brief feedback but don't execute
-                // TODO: Could show a brief "already running" message
+                // Already running - don't execute
                 false
             },
             (CommandType::ServiceStop, Some("inactive") | Some("failed") | Some("dead")) => {
-                // Already stopped - show brief feedback but don't execute  
-                // TODO: Could show a brief "already stopped" message
+                // Already stopped - don't execute  
                 false
             },
             (_, None) => {
@@ -456,36 +449,51 @@ impl TuiApp {
         
         if should_execute {
             if let Some(host_widgets) = self.host_widgets.get_mut(hostname) {
-                host_widgets.command_status = Some(CommandStatus::InProgress {
-                    command_type,
-                    target,
-                    start_time: Instant::now(),
-                });
+                // Store the pending transition for immediate visual feedback
+                host_widgets.pending_service_transitions.insert(
+                    target.clone(), 
+                    (command_type, current_status.unwrap_or_else(|| "unknown".to_string()))
+                );
             }
         }
         
         should_execute
     }
 
-    /// Check for command timeouts and automatically clear them
-    pub fn check_command_timeouts(&mut self) {
-        let now = Instant::now();
-        let mut hosts_to_clear = Vec::new();
-        
-        for (hostname, host_widgets) in &self.host_widgets {
-            if let Some(CommandStatus::InProgress { command_type: _, start_time, .. }) = &host_widgets.command_status {
-                let timeout_duration = Duration::from_secs(30); // 30 seconds for service commands
-                
-                if now.duration_since(*start_time) > timeout_duration {
-                    hosts_to_clear.push(hostname.clone());
+    /// Clear pending transitions when real status updates arrive
+    fn clear_completed_transitions(&mut self, hostname: &str, service_metrics: &[&Metric]) {
+        if let Some(host_widgets) = self.host_widgets.get_mut(hostname) {
+            let mut completed_services = Vec::new();
+            
+            // Check each pending transition to see if real status has changed
+            for (service_name, (command_type, original_status)) in &host_widgets.pending_service_transitions {
+                // Look for status metric for this service
+                for metric in service_metrics {
+                    if metric.name == format!("service_{}_status", service_name) {
+                        let new_status = metric.value.as_string();
+                        
+                        // Check if status has changed from original (command completed)
+                        if &new_status != original_status {
+                            // Verify it changed in the expected direction
+                            let expected_change = match command_type {
+                                CommandType::ServiceStart => &new_status == "active",
+                                CommandType::ServiceStop => &new_status != "active",
+                                CommandType::ServiceRestart => true, // Any change indicates restart completed
+                                _ => false,
+                            };
+                            
+                            if expected_change {
+                                completed_services.push(service_name.clone());
+                            }
+                        }
+                        break;
+                    }
                 }
             }
-        }
-        
-        // Clear timed out commands
-        for hostname in hosts_to_clear {
-            if let Some(host_widgets) = self.host_widgets.get_mut(&hostname) {
-                host_widgets.command_status = None;
+            
+            // Remove completed transitions
+            for service_name in completed_services {
+                host_widgets.pending_service_transitions.remove(&service_name);
             }
         }
     }
@@ -614,14 +622,14 @@ impl TuiApp {
         // Render services widget for current host
         if let Some(hostname) = self.current_host.clone() {
             let is_focused = self.focused_panel == PanelType::Services;
-            let (scroll_offset, command_status) = {
+            let (scroll_offset, pending_transitions) = {
                 let host_widgets = self.get_or_create_host_widgets(&hostname);
-                (host_widgets.services_scroll_offset, host_widgets.command_status.clone())
+                (host_widgets.services_scroll_offset, host_widgets.pending_service_transitions.clone())
             };
             let host_widgets = self.get_or_create_host_widgets(&hostname);
             host_widgets
                 .services_widget
-                .render_with_command_status(frame, content_chunks[1], is_focused, scroll_offset, command_status.as_ref()); // Services takes full right side
+                .render_with_transitions(frame, content_chunks[1], is_focused, scroll_offset, &pending_transitions); // Services takes full right side
         }
 
         // Render statusbar at the bottom