Fix autofocus on dynamically inserted forms, remove this.blur() handlers

form_controller.connect() now blurs the previously focused element and
explicitly focuses the [autofocus] element when a form is inserted into
the DOM (via Turbo Stream). Only runs when an [autofocus] element is
present, so closing forms and other stream updates are unaffected.

Remove all onclick='this.blur()' inline handlers from templates — they
were a workaround for the same autofocus problem, now solved properly
via the Stimulus lifecycle.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/views/quantities/index.html.erb

@@ -1,7 +1,7 @@
 <div class="rightside-area buttongrid">
   <% if current_user.at_least(:active) %>
     <%= image_link_to t('.new_quantity'), 'plus-outline', new_quantity_path,
-      id: dom_id(Quantity, :new, :link), onclick: 'this.blur();',
+      id: dom_id(Quantity, :new, :link),
       data: {turbo_stream: true} %>
   <% end %>
   <%#= image_link_to t('.import_quantities'), 'download-outline', default_quantities_path,