feat: implement CSV export for the asset list

frontend/app/(dashboard)/assets/page.tsx

@@ -9,6 +9,7 @@ import { ConditionBadge } from "@/components/assets/condition-badge";
 import { CreateAssetModal } from "@/components/assets/create-asset-modal";
 import { useAssets } from "@/lib/query/hooks/useAssets";
 import { AssetStatus, AssetCondition } from "@/lib/query/types/asset";
+import { ExportAssetsButton } from "@/opsce/features/assets/ExportAssetsButton";
 
 const STATUS_OPTIONS = ["All", ...Object.values(AssetStatus)];
 
@@ -42,10 +43,13 @@ export default function AssetsPage() {
               : "No assets yet"}
           </p>
         </div>
-        <Button onClick={() => setShowModal(true)}>
-          <Plus size={16} className="mr-1.5" />
-          Register Asset
-        </Button>
+        <div className="flex items-center gap-2">
+          <ExportAssetsButton />
+          <Button onClick={() => setShowModal(true)}>
+            <Plus size={16} className="mr-1.5" />
+            Register Asset
+          </Button>
+        </div>
       </div>
 
       {/* Filters */}

frontend/opsce/features/assets/ExportAssetsButton.tsx

@@ -0,0 +1,65 @@
+'use client';
+
+import { useState, useCallback } from 'react';
+import { Download } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import { toast } from '@/components/ui/toast';
+import { api } from '@/lib/api';
+
+interface ExportAssetsButtonProps {
+  filters?: Record<string, string | undefined>;
+}
+
+export function ExportAssetsButton({ filters = {} }: ExportAssetsButtonProps) {
+  const [loading, setLoading] = useState(false);
+
+  const handleExport = useCallback(async () => {
+    setLoading(true);
+    try {
+      // Build query params from active filters
+      const params = new URLSearchParams();
+      params.set('format', 'csv');
+      Object.entries(filters).forEach(([key, value]) => {
+        if (value) params.set(key, value);
+      });
+
+      const response = await api.get(`/assets/export?${params.toString()}`, {
+        responseType: 'blob',
+        timeout: 30000, // 30 second timeout for large exports
+      });
+
+      const blob = new Blob([response.data], { type: 'text/csv' });
+      const url = window.URL.createObjectURL(blob);
+      const link = document.createElement('a');
+      link.href = url;
+      link.download = `assets_export_${new Date().toISOString().split('T')[0]}.csv`;
+      document.body.appendChild(link);
+      link.click();
+      document.body.removeChild(link);
+      window.URL.revokeObjectURL(url);
+
+      toast.success('Assets exported as CSV successfully');
+    } catch (err: unknown) {
+      console.error('Export failed:', err);
+      const errorMessage =
+        (err as { response?: { status?: number } })?.response?.status === 403
+          ? 'You do not have permission to export assets.'
+          : 'Failed to export assets. Please try again.';
+      toast.error(errorMessage);
+    } finally {
+      setLoading(false);
+    }
+  }, [filters]);
+
+  return (
+    <Button
+      size="sm"
+      variant="outline"
+      onClick={handleExport}
+      loading={loading}
+    >
+      <Download size={14} className="mr-1.5" />
+      Export CSV
+    </Button>
+  );
+}