Update system widget layout with section headers

- Add section headers: CPU, RAM, Storage as plain titles
- Remove status icons from section headers
- Keep status icons only on data lines (Load, Usage, /tmp, filesystems)
- Restore (Single) label for all storage types
- Improve visual hierarchy with clear section separation

dashboard/src/ui/widgets/system.rs

@@ -254,11 +254,7 @@ impl SystemWidget {
                 _ => "—% —GB/—GB".to_string(),
             };
             
-            let pool_label = if pool.pool_type.to_lowercase() == "single" {
-                format!("{}:", pool.mount_point)
-            } else {
-                format!("{} ({}):", pool.mount_point, pool.pool_type)
-            };
+            let pool_label = format!("{} ({}):", pool.mount_point, pool.pool_type);
             let pool_spans = StatusIcons::create_status_spans(
                 pool.status.clone(),
                 &pool_label
@@ -421,14 +417,15 @@ impl Widget for SystemWidget {
             Span::styled(format!("Agent: {}", short_hash), Typography::secondary())
         ]));
 
-        // Empty line
-        lines.push(Line::from(vec![Span::raw("")]));
-
         // CPU section
+        lines.push(Line::from(vec![
+            Span::styled("CPU:", Typography::widget_title())
+        ]));
+        
         let load_text = self.format_cpu_load();
         let cpu_spans = StatusIcons::create_status_spans(
             self.cpu_status.clone(),
-            &format!("CPU: {}", load_text)
+            &format!("Load: {}", load_text)
         );
         lines.push(Line::from(cpu_spans));
         
@@ -439,10 +436,14 @@ impl Widget for SystemWidget {
         ]));
 
         // RAM section
+        lines.push(Line::from(vec![
+            Span::styled("RAM:", Typography::widget_title())
+        ]));
+        
         let memory_text = self.format_memory_usage();
         let memory_spans = StatusIcons::create_status_spans(
             self.memory_status.clone(),
-            &format!("RAM: {}", memory_text)
+            &format!("Usage: {}", memory_text)
         );
         lines.push(Line::from(memory_spans));
 
@@ -456,10 +457,12 @@ impl Widget for SystemWidget {
         ));
         lines.push(Line::from(tmp_spans));
 
-        // Empty line before storage
-        lines.push(Line::from(vec![Span::raw("")]));
-
-        // Storage section with tree structure
+        // Storage section
+        lines.push(Line::from(vec![
+            Span::styled("Storage:", Typography::widget_title())
+        ]));
+        
+        // Storage items
         lines.extend(self.render_storage());
 
         let paragraph = Paragraph::new(Text::from(lines));