clean up & save onboarding process as state

src/app/auth/import/index.tsx

@@ -1,6 +1,19 @@
+import { useEffect } from 'react';
 import { Outlet } from 'react-router-dom';
 
+import { useOnboarding } from '@stores/onboarding';
+import { useStronghold } from '@stores/stronghold';
+
 export function AuthImportScreen() {
+  const [step, tmpPrivkey] = useOnboarding((state) => [state.step, state.tempPrivkey]);
+  const setPrivkey = useStronghold((state) => state.setPrivkey);
+
+  useEffect(() => {
+    if (step) {
+      setPrivkey(tmpPrivkey);
+    }
+  }, [tmpPrivkey]);
+
   return (
     <div className="flex h-full w-full items-center justify-center">
       <Outlet />