Redirect User to Proposal Creation Form After Sign-Up/Sign-In

[simonaszilinskas]

Description:
Currently, when a user who is not signed in starts creating an anonymous proposal, they see a top banner prompting them to sign up or sign in. The expected behavior is that, after signing up or logging in, the user should be automatically redirected back to the proposal creation form they were working on. This ensures a seamless and user-friendly experience, preventing loss of progress and encouraging user engagement.

Steps to Reproduce:

1. Visit the website as a non-signed-in user.
2. Begin creating a proposal anonymously.
3. Click on the sign-up/sign-in prompt in the top banner.
4. Complete the sign-up or sign-in process.

Expected Result:
After sign-up/sign-in, the user is redirected back to the proposal creation form with any entered data retained.