Change CAPTCHA handling to be only on email verification

This simplifies the implementation considerably, and while not providing
ideal UX, it's the most flexible approach.

app/views/about/_registration.html.haml

@@ -21,9 +21,6 @@
     .fields-group
       = f.input :agreement, as: :boolean, wrapper: :with_label, label: t('auth.checkbox_agreement_html', rules_path: about_more_path, terms_path: terms_path), required: true, disabled: closed_registrations?
 
-    .fields-group
-      = render_captcha_if_needed
-
     .actions
       = f.button :button, sign_up_message, type: :submit, class: 'button button-primary', disabled: closed_registrations?
 

app/views/admin/settings/edit.html.haml

@@ -45,7 +45,7 @@
 
   - if captcha_available?
     .fields-group
-      = f.input :captcha_mode, as: :radio_buttons, collection: %w(disabled registration-form email-confirmation), include_blank: false, wrapper: :with_block_label, label_method: ->(type) { safe_join([t("admin.settings.captcha.#{type}.title"), content_tag(:span, t("admin.settings.captcha.#{type}.desc_html"), class: 'hint')])}, label: t('admin.settings.captcha.title'), hint: t('admin.settings.captcha.desc_html')
+      = f.input :captcha_enabled, as: :boolean, wrapper: :with_label, label: t('admin.settings.captcha_enabled.title'), hint: t('admin.settings.captcha_enabled.desc_html')
 
   %hr.spacer/
 

app/views/auth/confirmations/captcha.html.haml

@@ -5,7 +5,7 @@
   = hidden_field_tag :confirmation_token, params[:confirmation_token]
 
   .field-group
-    = render_captcha_if_needed
+    = render_captcha
 
   .actions
     %button.button= t('challenge.continue')

app/views/auth/registrations/new.html.haml

@@ -38,9 +38,6 @@
   .fields-group
     = f.input :agreement, as: :boolean, wrapper: :with_label, label: whitelist_mode? ? t('auth.checkbox_agreement_without_rules_html', terms_path: terms_path) : t('auth.checkbox_agreement_html', rules_path: about_more_path, terms_path: terms_path), required: true
 
-  .field-group
-    = render_captcha_if_needed
-
   .actions
     = f.button :button, @invite.present? ? t('auth.register') : sign_up_message, type: :submit