Improve service selection: preserve status colors and skip sub-services

Selection Behavior Improvements:
- Limit selection to parent services only (docker, nginx, postgresql, etc.)
- Skip sub-services in navigation (no longer select nginx sub-sites)
- Up/Down arrows now move between actionable services only

Visual Enhancement:
- Preserve original status colors in selection highlighting
- Selected services show blue background with status foreground colors
- Green text for active services, red for failed, even when selected
- Maintains visual health status information during selection

Selection Logic:
- Add parent service index mapping for accurate selection tracking
- Only count parent services in total service count
- Calculate proper parent service index from display line position
- Ensure selection highlights only apply to parent services

This creates a cleaner UX where users only select services they can
actually control (start/stop/restart) while maintaining visual health
status indicators through preserved status colors.

dashboard/src/ui/widgets/services.rs

@@ -243,19 +243,38 @@ impl ServicesWidget {
         display_lines.get(self.selected_index).map(|(name, _, _, _)| name.clone())
     }
 
-    /// Get total count of services (parent + sub-services)
+    /// Get total count of selectable services (parent services only, not sub-services)
     pub fn get_total_services_count(&self) -> usize {
-        let mut count = 0;
+        // Only count parent services - sub-services are not selectable
+        self.parent_services.len()
+    }
+
+    /// Calculate which parent service index corresponds to a display line index
+    fn calculate_parent_service_index(&self, display_line_index: &usize) -> usize {
+        // Build the same display list to map line index to parent service index
+        let mut parent_index = 0;
+        let mut line_index = 0;
         
-        // Count parent services
-        count += self.parent_services.len();
-        
-        // Count sub-services
-        for sub_list in self.sub_services.values() {
-            count += sub_list.len();
+        let mut parent_services: Vec<_> = self.parent_services.iter().collect();
+        parent_services.sort_by(|(a, _), (b, _)| a.cmp(b));
+
+        for (parent_name, _) in parent_services {
+            if line_index == *display_line_index {
+                return parent_index;
+            }
+            line_index += 1; // Parent service line
+            
+            // Skip sub-services but count them in line_index
+            if let Some(sub_list) = self.sub_services.get(parent_name) {
+                line_index += sub_list.len();
+            }
+            
+            parent_index += 1;
         }
         
-        count
+        // If we get here, the display_line_index was probably for a sub-service
+        // Return the last valid parent index (should not happen with our logic)
+        parent_index.saturating_sub(1)
     }
 }
 
@@ -481,7 +500,15 @@ impl ServicesWidget {
             for (i, (line_text, line_status, is_sub, sub_info)) in visible_lines.iter().enumerate()
             {
                 let actual_index = effective_scroll + i; // Real index in the full list
-                let is_selected = actual_index == self.selected_index;
+                
+                // Only parent services can be selected - calculate parent service index
+                let is_selected = if !*is_sub {
+                    // This is a parent service - count how many parent services came before this one
+                    let parent_index = self.calculate_parent_service_index(&actual_index);
+                    parent_index == self.selected_index
+                } else {
+                    false // Sub-services are never selected
+                };
                 
                 let mut spans = if *is_sub && sub_info.is_some() {
                     // Use custom sub-service span creation
@@ -492,12 +519,11 @@ impl ServicesWidget {
                     StatusIcons::create_status_spans(*line_status, line_text)
                 };
                 
-                // Apply selection highlighting to spans
-                if is_selected {
+                // Apply selection highlighting to parent services only, preserving status colors
+                if is_selected && !*is_sub {
                     for span in spans.iter_mut() {
-                        span.style = span.style
-                            .bg(Theme::highlight())
-                            .fg(Theme::background());
+                        // Keep the original foreground color (status color) but add background highlight
+                        span.style = span.style.bg(Theme::highlight());
                     }
                 }