Reset onboarding for all existing users (v2 key)

frontend/src/pages/Dashboard.tsx

@@ -17,11 +17,11 @@ export default function Dashboard() {
   const [discovering, setDiscovering] = useState(false)
   const [loading, setLoading] = useState(true)
   const [showOnboarding, setShowOnboarding] = useState(
-    !localStorage.getItem('vynl_onboarding_done')
+    !localStorage.getItem('vynl_onboarding_v2')
   )
 
   const handleOnboardingComplete = () => {
-    localStorage.setItem('vynl_onboarding_done', 'true')
+    localStorage.setItem('vynl_onboarding_v2', 'true')
     setShowOnboarding(false)
   }