✨ Add Rails 8 style authentication

[jbakerdev]

I started my own simple auth way back, but never finished (and never pushed more than the user model). Adding the default rails 8 auth as a starting point for other things.

• Remove my first attempt, then run the rails 8 authentication generator

• Customize the boilerplate:

  • Build out some user fixtures and tests
  • Use view components where practical
  • Change verbiage to be Tron-inspired ("Identify yourself, User") because I'm feeling retro

• Changes:

  • Allow unauthenticated access on home page

• Additions:

  • Add sign out button to navbar
  • Add a system test helper for authentication (the helper built into Rails 8.1 only works for controller tests)