Consolidate HTTP checking and improve display formatting

- Change site latency timeout from 5s to 2s for faster error detection
- Replace curl with reqwest for external connectivity checks (consistent timeouts)
- Remove unused gitea-specific monitoring functionality
- Update dashboard: show 'unreachable' for latency > 2000ms, add arrows (→) between site and latency
- Add percentage signs to CPU metrics display
- All HTTP requests now use reqwest with 2-second timeouts

dashboard/src/ui/services.rs

@@ -110,9 +110,9 @@ fn render_metrics(
             let service_name_with_latency = if let Some(parent) = &svc.sub_service {
                 if parent == "nginx" {
                     match &svc.latency_ms {
-                        Some(latency) if *latency >= 5000.0 => format!("{} unreachable", svc.name), // Timeout (5s+)
-                        Some(latency) => format!("{} {:.0}ms", svc.name, latency),
-                        None => format!("{} unreachable", svc.name), // Connection failed
+                        Some(latency) if *latency >= 2000.0 => format!("{} → unreachable", svc.name), // Timeout (2s+)
+                        Some(latency) => format!("{} → {:.0}ms", svc.name, latency),
+                        None => format!("{} → unreachable", svc.name), // Connection failed
                     }
                 } else {
                     svc.name.clone()
@@ -178,9 +178,9 @@ fn format_memory_value(used: f32, quota: f32) -> String {
 
 fn format_cpu_value(cpu_percent: f32) -> String {
     if cpu_percent >= 0.1 {
-        format!("{:.1}", cpu_percent)
+        format!("{:.1}%", cpu_percent)
     } else {
-        "0.0".to_string()
+        "0.0%".to_string()
     }
 }