refactor: optimize system health monitoring and UI interactions

- Removed unnecessary delay in chat redirection for immediate user feedback.
- Enhanced TitleBar component with a system health indicator, displaying RAM and CPU usage.
- Implemented optimistic UI updates for model downloads and Ollama installation, improving responsiveness.
- Introduced background health monitoring to prevent resource overload during operations.
- Added cleanup logic for child processes to ensure proper resource management during application shutdown.

components/setup/model-selector.tsx

@@ -115,19 +115,21 @@ export function ModelSelector({ recommendation, onComplete }: ModelSelectorProps
   };
 
   const handleDownload = async () => {
+    // Optimistic UI: atualizar estado imediatamente antes da chamada Tauri
     setIsDownloading(true);
     setDownloadProgress(0);
     setDownloadStatus("Iniciando download...");
-    try {
-      await invoke('pull_model', { name: selectedModelId });
-      // O status será atualizado pelo listener quando o download completar
-      // Não precisamos setar aqui pois o listener já faz isso
-    } catch (error) {
-      console.error("Download failed", error);
-      setDownloadStatus("Falha no download. Tente novamente.");
-      setDownloadProgress(0);
-      setIsDownloading(false);
-    }
+    
+    // Chamar Tauri em background (não bloquear)
+    invoke('pull_model', { name: selectedModelId })
+      .catch((error) => {
+        console.error("Download failed", error);
+        setDownloadStatus("Falha no download. Tente novamente.");
+        setDownloadProgress(0);
+        setIsDownloading(false);
+      });
+    // O status será atualizado pelo listener quando o download completar
+    // Não precisamos aguardar aqui pois o listener já faz isso
   };
 
   return (

components/titlebar.tsx

@@ -4,9 +4,12 @@ import { useEffect, useState } from 'react';
 import { getCurrentWindow } from '@tauri-apps/api/window';
 import { Minus, Square, X } from 'lucide-react';
 import { cn } from '@/lib/utils';
+import { useSystemHealth } from '@/hooks/use-system-health';
+import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '@/components/ui/tooltip';
 
 export function TitleBar() {
   const [isMaximized, setIsMaximized] = useState(false);
+  const health = useSystemHealth();
 
   useEffect(() => {
     let isMounted = true;
@@ -94,6 +97,28 @@ export function TitleBar() {
         <span className="text-sm font-medium text-sidebar-foreground">
           OllaHub
         </span>
+        
+        {/* Indicador de saúde do sistema */}
+        <TooltipProvider>
+          <Tooltip>
+            <TooltipTrigger asChild>
+              <div
+                className={cn(
+                  "w-2 h-2 rounded-full shrink-0",
+                  health.status === 'healthy' && "bg-green-500",
+                  health.status === 'warning' && "bg-yellow-500",
+                  health.status === 'critical' && "bg-red-500"
+                )}
+              />
+            </TooltipTrigger>
+            <TooltipContent side="bottom" className="text-xs">
+              <p>{health.message}</p>
+              <p className="text-muted-foreground mt-1">
+                RAM: {health.ram_percent.toFixed(1)}% | CPU: {health.cpu_percent.toFixed(1)}%
+              </p>
+            </TooltipContent>
+          </Tooltip>
+        </TooltipProvider>
       </div>
 
       {/* Controles de janela */}