Implement transparent password hash migration

Add has_secure_password and bcrypt while retaining compatibility with
legacy SHA-1 password hashes. Existing users are upgraded to
password_digest on their next successful login.

Add regression tests covering both legacy and modern authentication
paths.

1 files changed, 1 insertions, 0 deletions

diff --git a/Gemfile b/Gemfile
index 97257a9..cad34df 100644
--- a/Gemfile
+++ b/Gemfile
@@ -38,6 +38,7 @@ gem 'rails_icons'
 gem 'globalize',      '~> 7.0'    # translated model attributes (Page title/abstract/body)
 gem 'acts_as_list'                # page revision ordering
 gem 'will_paginate',  '~> 3.0'
+gem 'bcrypt',         '~> 3.1'
 
 # Pinned to git until a release widens the activerecord < 8.1 ceiling.
 # Both gems work correctly on Rails 8.1; the gemspec constraint is overly conservative.