git CLDC-1183: use email where no user name

app/helpers/tab_nav_helper.rb

@@ -2,7 +2,8 @@ module TabNavHelper
   include GovukLinkHelper
 
   def user_cell(user)
-    [govuk_link_to(user.name, user, class: "govuk-!-font-weight-bold"), user.email].join("\n")
+    link_text = user.name.presence || user.email
+    [govuk_link_to(link_text, user, class: "govuk-!-font-weight-bold"), user.email].join("\n")
   end
 
   def org_cell(user)

app/views/users/new.html.erb

@@ -17,7 +17,8 @@
       </h1>
 
       <%= f.govuk_text_field :name,
-        autocomplete: "name" %>
+        autocomplete: "name",
+        label: { text: "Name (optional)" } %>
 
       <%= f.govuk_email_field :email,
         label: { text: "Email address" },

app/views/users/show.html.erb

@@ -1,4 +1,4 @@
-<% content_for :title, current_user == @user ? "Your account" : "#{@user.name}’s account" %>
+<% content_for :title, current_user == @user ? "Your account" : "#{@user.name.presence || @user.email}’s account" %>
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
@@ -9,7 +9,6 @@
     <h2 class="govuk-heading-m">
       Personal details
     </h2>
-
     <%= govuk_summary_list do |summary_list| %>
       <%= summary_list.row do |row|
             row.key { "Name" }