Admin role

[benjaminpjones]

This adds the admin role and one elevated privilege: the ability to make another user an admin.

Screencast_20241123_232459.webm

A couple required, but not directly related changes:

• Created User page, where we add the "Make Admin" button
• Fixed up some User types:
  • id should be required in UserResponse, except for DB code
  • Some instances of Userchanged to UserResponse.
    • I think these are generally interchangeable (except for the optional id issue). I should follow up to merge the two.

[benjaminpjones]

Updates:

• much DRYer requests
• fix watchEffect issue
• register success in the UI by updaing user.value

[merowin]

Though I'm not an expert on security, it looks good to me. Nice job! 😄

I left a couple of thoughts, but nothing important.