fix(templates): forms and detail lists fit a phone screen

Column offsets without a breakpoint applied below it, where the column
is already full width, so the change password, compute, user, VM
create and VM settings forms ran past the right edge on a phone. Each
offset now starts at its column's breakpoint. The interface and network
detail lists were rows directly inside rows and sit in a column now;
the compute form loses a Bootstrap 3 thumbnail padding that broke its
gutters, and the add-rule dialog's hint is no longer cut off. The page
test checks both grid rules on every page.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

computes/templates/computes/form.html

@@ -12,7 +12,7 @@
     </div>
 </div>
 <div class="row">
-    <div class="thumbnail col-sm-10 offset-1">
+    <div class="col-sm-10 offset-sm-1">
         <form id="create-update" action="" method="post">
             {% csrf_token %}
             {% bootstrap_form form layout='horizontal' %}