A couple of Devise bug fixes

[nathanmsmith]

Description

• Fix broken sign_in link
• Remember users after they log in

Deployment

• I am making a frontend change, which will be auto-deployed via Heroku.
• I am making a Ruby change, which will be auto-deployed via Heroku.
  • I have added one or more gems, and run rake sorbet:update:all to generate their types.
  • I have added or changed a model, and run rake sorbet:update:all to generate their types.
• I am making a database change, which I will manually deploy after my branch is merged.
  • I have migrated the database using env RAILS_ENV=production rails db:migrate.
  • I have updated the entity relationship diagram via bundle exec erd.
  • I have updated the affected Administrate model dashboards to reflect my DB changes.
• I am making a Go Lambda change, which I will manually deploy after my branch is merged.
  • I have deployed the lambdas using make deploy.
• There are other deployment steps I must take after merge, which are: