fixup: return the user entity on login

Dependencies

• [2] NAOPOQY3 login: redirect to the current-user page
• [3] LZVO64YG Merge in the first bits of the API work
• [4] WDKFN4B2 Make sign in a modal dialog box rather than a separate page
• [*] XJRJ4J7M Add user registration

Change contents

• replacement in src/lib/Hydra/Controller/User.pm at line 43
  [2.86]→[2.86:107](∅→∅)
  − entity => {}
  [2.86]

  [2.107]
  + entity => $c->model("DB::Users")->find($c->user->username)