Add service metrics from systemctl (memory, uptime, restarts)

Shared:
- Add memory_bytes, restart_count, uptime_seconds to ServiceData

Agent:
- Add new fields to ServiceStatusInfo struct
- Fetch MemoryCurrent, NRestarts, ExecMainStartTimestamp from systemctl show
- Calculate uptime from start timestamp
- Parse and populate new fields in ServiceData
- Remove unused load_state and sub_state fields

Dashboard:
- Add memory_bytes, restart_count, uptime_seconds to ServiceInfo
- Update header: Service, Status, RAM, Uptime, ↻ (restarts)
- Format memory as MB/GB
- Format uptime as Xd Xh, Xh Xm, or Xm
- Show restart count with ! prefix if > 0 to indicate instability

All metrics obtained from single systemctl show call - zero overhead.

dashboard/src/ui/widgets/services.rs

@@ -31,6 +31,9 @@ struct ServiceInfo {
     metrics: Vec<(String, f32, Option<String>)>, // (label, value, unit)
     widget_status: Status,
     service_type: String, // "nginx_site", "container", "image", or empty for parent services
+    memory_bytes: Option<u64>,
+    restart_count: Option<u32>,
+    uptime_seconds: Option<u64>,
 }
 
 impl ServicesWidget {
@@ -84,7 +87,7 @@ impl ServicesWidget {
         // Convert Status enum to display text
         let status_str = match info.widget_status {
             Status::Ok => "active",
-            Status::Inactive => "inactive", 
+            Status::Inactive => "inactive",
             Status::Critical => "failed",
             Status::Pending => "pending",
             Status::Warning => "warning",
@@ -92,9 +95,43 @@ impl ServicesWidget {
             Status::Offline => "offline",
         };
 
+        // Format memory
+        let memory_str = info.memory_bytes.map_or("-".to_string(), |bytes| {
+            let mb = bytes as f64 / (1024.0 * 1024.0);
+            if mb >= 1000.0 {
+                format!("{:.1}G", mb / 1024.0)
+            } else {
+                format!("{:.0}M", mb)
+            }
+        });
+
+        // Format uptime
+        let uptime_str = info.uptime_seconds.map_or("-".to_string(), |secs| {
+            let days = secs / 86400;
+            let hours = (secs % 86400) / 3600;
+            let mins = (secs % 3600) / 60;
+
+            if days > 0 {
+                format!("{}d{}h", days, hours)
+            } else if hours > 0 {
+                format!("{}h{}m", hours, mins)
+            } else {
+                format!("{}m", mins)
+            }
+        });
+
+        // Format restarts (show "!" if > 0 to indicate instability)
+        let restart_str = info.restart_count.map_or("-".to_string(), |count| {
+            if count > 0 {
+                format!("!{}", count)
+            } else {
+                "0".to_string()
+            }
+        });
+
         format!(
-            "{:<23} {:<10}",
-            short_name, status_str
+            "{:<23} {:<10} {:<8} {:<8} {:<5}",
+            short_name, status_str, memory_str, uptime_str, restart_str
         )
     }
 
@@ -280,6 +317,9 @@ impl Widget for ServicesWidget {
                 metrics: Vec::new(), // Parent services don't have custom metrics
                 widget_status: service.service_status,
                 service_type: String::new(), // Parent services have no type
+                memory_bytes: service.memory_bytes,
+                restart_count: service.restart_count,
+                uptime_seconds: service.uptime_seconds,
             };
             self.parent_services.insert(service.name.clone(), parent_info);
 
@@ -296,6 +336,9 @@ impl Widget for ServicesWidget {
                         metrics,
                         widget_status: sub_service.service_status,
                         service_type: sub_service.service_type.clone(),
+                        memory_bytes: None, // Sub-services don't have individual metrics yet
+                        restart_count: None,
+                        uptime_seconds: None,
                     };
                     sub_list.push((sub_service.name.clone(), sub_info));
                 }
@@ -338,6 +381,9 @@ impl ServicesWidget {
                                     metrics: Vec::new(),
                                     widget_status: Status::Unknown,
                                     service_type: String::new(),
+                                    memory_bytes: None,
+                                    restart_count: None,
+                                    uptime_seconds: None,
                                 });
 
                         if metric.name.ends_with("_status") {
@@ -364,6 +410,9 @@ impl ServicesWidget {
                                     metrics: Vec::new(),
                                     widget_status: Status::Unknown,
                                     service_type: String::new(), // Unknown type in legacy path
+                                    memory_bytes: None,
+                                    restart_count: None,
+                                    uptime_seconds: None,
                                 },
                             ));
                             &mut sub_service_list.last_mut().unwrap().1
@@ -429,8 +478,8 @@ impl ServicesWidget {
 
         // Header
         let header = format!(
-            "{:<25} {:<10}",
-            "Service:", "Status:"
+            "{:<25} {:<10} {:<8} {:<8} {:<5}",
+            "Service:", "Status:", "RAM:", "Uptime:", "↻:"
         );
         let header_para = Paragraph::new(header).style(Typography::muted());
         frame.render_widget(header_para, content_chunks[0]);