use split view by default in amendments

app/cells/decidim/diff/attribute.erb

@@ -0,0 +1,16 @@
+<div class="diff-for-<%= data[:label].parameterize %>">
+  <div class="row">
+    <h3 class="section-heading mediumlarge-12 columns">
+      <%= data[:label] %>
+    </h3>
+  </div>
+
+  <div class="row diff_view diff_view_split" id="attribute-diff-unified-<%= data[:label].parameterize %>-<%= format %>">
+    <%= diff_split(data, "left", format) %>
+    <%= diff_split(data, "right", format) %>
+  </div>
+
+  <div class="row diff_view diff_view_unified hide" id="attribute-diff-unified-<%= data[:label].parameterize %>-<%= format %>">
+    <%= diff_unified(data, format) %>
+  </div>
+</div>

app/cells/decidim/diff/diff_mode_dropdown.erb

@@ -0,0 +1,34 @@
+<div class="diff-view-by show-for-mediumlarge">
+  <div class="diff-view-by__dropdown">
+    <span class="diff-view-by__text">
+      <%= t("versions.dropdown.choose_diff_view_mode") %>
+    </span>
+
+    <ul class="dropdown menu" data-dropdown-menu
+      data-autoclose="false"
+      data-disable-hover="true"
+      data-click-open="true"
+      data-close-on-click="true"
+      role="menubar">
+      <li class="is-dropdown-submenu-parent" role="presentation">
+        <a href="#diffmode-chooser-menu" id="diff-view-selected" aria-controls="diffmode-chooser-menu" aria-haspopup="true" aria-label="<%= t("versions.dropdown.choose_diff_view_mode_menu") %>" role="menuitem">
+          <%= t("versions.dropdown.option_split") %>
+        </a>
+
+        <ul class="menu is-dropdown-submenu" id="diffmode-chooser-menu" role="menu" aria-labelledby="diff-view-selected">
+          <li role="presentation">
+            <%= link_to "#diff-view-split", class: "diff-view-mode diff-view-split", id:"diff-view-split", role: "menuitem" do %>
+              <%= t("versions.dropdown.option_split") %>
+            <% end %>
+          </li>
+
+          <li role="presentation">
+            <%= link_to "#diff-view-unified", class: "diff-view-mode diff-view-unified", id:"diff-view-unified", role: "menuitem" do %>
+              <%= t("versions.dropdown.option_unified") %>
+            <% end %>
+          </li>
+        </ul>
+      </li>
+    </ul>
+  </div>
+</div>

spec/lib/overrides_spec.rb

@@ -25,6 +25,8 @@
       "/app/views/decidim/devise/shared/_omniauth_buttons_mini.html.erb" => "d3a413ce7c64959eee3b912406075f84",
       # cells
       "/app/cells/decidim/date_range/show.erb" => "7e050b942e447386fc96ef6528039cec",
+      "/app/cells/decidim/diff/attribute.erb" => "d648bc8e71e27c404d82132d6e3c3241",
+      "/app/cells/decidim/diff/diff_mode_dropdown.erb" => "770563c121c875159a88cd5e142658e3",
       # other overrides
       "/app/helpers/decidim/card_helper.rb" => "b9e7f943ae7c289b2855d328de7b371b",
       "/app/commands/decidim/amendable/accept.rb" => "c561b69a7bd5b68dfc4684c11001cb2c",