Merge branch 'admin-improvements-and-styling-fixes' into 'main'

app/views/admin/users/index.html.erb

app/views/admin/users/new.html.erb

app/views/admin/users/show.html.erb

app/views/devise/registrations/edit.html.erb

app/views/devise/registrations/new.html.erb

app/views/devise/sessions/new.html.erb

app/views/devise/shared/_links.html.erb

app/views/layouts/admin.html.erb

app/views/layouts/application.html.erb

app/views/shared/_admin_nav.html.erb

config/routes.rb

db/migrate/20250304101405_migrate_to_rbac_system.rb

db/migrate/20250308080600_add_admin_role_and_permissions.rb

db/schema.rb

db/seeds.rb

lib/tasks/admin.rake