Make it clear this is just notifications, not comprehensive activity

app/mailers/notification/bundle_mailer.rb

@@ -11,6 +11,6 @@ class Notification::BundleMailer < ApplicationMailer
 
     mail \
       to: bundle.user.identity.email_address,
-      subject: "Fizzy#{ " (#{ Current.account.name })" if @user.identity.accounts.many? }: Latest Activity"
+      subject: "Fizzy#{ " (#{ Current.account.name })" if @user.identity.accounts.many? }: New notifications"
   end
 end

app/views/mailers/notification/bundle_mailer/notification.html.erb

@@ -1,6 +1,6 @@
 <tr>
   <td>
-    <h1 class="title">Everything since <%= @bundle.starts_at.strftime("%-l%P on %A, %B %-d") %></h1>
+    <h1 class="title">Notifications since <%= @bundle.starts_at.strftime("%-l%P on %A, %B %-d") %></h1>
     <p class="subtitle margin-block-end-double">
       You have <%= link_to pluralize(@notifications.count, "new notification"), notifications_url %><%= " in #{ Current.account.name }" if @user.identity.accounts.many? %>.
     </p>

app/views/mailers/notification/bundle_mailer/notification.text.erb

@@ -1,4 +1,4 @@
-Everything since <%= @bundle.starts_at.strftime("%-l%P on %A, %B %-d") %>
+Notifications since <%= @bundle.starts_at.strftime("%-l%P on %A, %B %-d") %>
 You have <%= pluralize @notifications.count, "new notification" %><%= " in #{ Current.account.name }" if @user.identity.accounts.many? %>.
 
 <% @notifications.group_by(&:card).each do |card, notifications| %>