feat: add sandbox risk confirmation and rejection screens

- Introduced `SandboxRiskDialog` to prompt users about risks when running outside a containerized environment.
- Added `SandboxRejectionScreen` for users who deny the sandbox risk confirmation, providing options to reload or restart the app.
- Updated settings view and danger zone section to manage sandbox warning preferences.
- Implemented a new API endpoint to check if the application is running in a containerized environment.
- Enhanced state management to handle sandbox warning settings across the application.

apps/ui/src/components/dialogs/sandbox-rejection-screen.tsx

@@ -0,0 +1,53 @@
+/**
+ * Sandbox Rejection Screen
+ *
+ * Shown in web mode when user denies the sandbox risk confirmation.
+ * Prompts them to either restart the app in a container or reload to try again.
+ */
+
+import { ShieldX, RefreshCw } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+
+export function SandboxRejectionScreen() {
+  const handleReload = () => {
+    // Clear the rejection state and reload
+    sessionStorage.removeItem('automaker-sandbox-denied');
+    window.location.reload();
+  };
+
+  return (
+    <div className="min-h-screen bg-background flex items-center justify-center p-4">
+      <div className="max-w-md w-full text-center space-y-6">
+        <div className="flex justify-center">
+          <div className="rounded-full bg-destructive/10 p-4">
+            <ShieldX className="w-12 h-12 text-destructive" />
+          </div>
+        </div>
+
+        <div className="space-y-2">
+          <h1 className="text-2xl font-semibold">Access Denied</h1>
+          <p className="text-muted-foreground">
+            You declined to accept the risks of running Automaker outside a sandbox environment.
+          </p>
+        </div>
+
+        <p className="text-sm text-muted-foreground">
+          For safer operation, consider running Automaker in Docker. See the README for
+          instructions.
+        </p>
+
+        <div className="pt-2">
+          <Button
+            variant="outline"
+            onClick={handleReload}
+            className="gap-2"
+            data-testid="sandbox-retry"
+          >
+            <RefreshCw className="w-4 h-4" />
+            Reload &amp; Try Again
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+}