feat: Rebranding von LeadFlow zu OnyvaLeads

Alle UI-Labels, Dateinamen, API-Bezeichner und package.json auf OnyvaLeads umgestellt.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/layout/TopBar.tsx

@@ -23,7 +23,7 @@ export function TopBar() {
   return (
     <header className="h-14 border-b border-[#1e1e2e] bg-[#111118]/80 backdrop-blur flex items-center justify-between px-6 flex-shrink-0">
       <div className="flex items-center gap-2 text-sm">
-        <span className="text-gray-500">LeadFlow</span>
+        <span className="text-gray-500">OnyvaLeads</span>
         <span className="text-gray-600">/</span>
         <span className="text-white font-medium">{label}</span>
       </div>