uploads: add column for error messages.

Change it so uploads store errors in an `error` column instead of in the
`status` field.

app/views/uploads/_table.html.erb

@@ -59,7 +59,7 @@
       <div>
         <strong>Error</strong>
         <span>
-          <%= upload.status.delete_prefix("error: ") %>
+          <%= upload.error %>
         </span>
       </div>
     <% end %>
@@ -72,11 +72,7 @@
   <% end %>
 
   <% t.column :status do |upload| %>
-    <% if upload.is_errored? %>
-      error
-    <% elsif !upload.is_completed? %>
-      <%= upload.status %>
-    <% end %>
+    <%= upload.status %>
   <% end %>
 <% end %>
 

app/views/uploads/show.html.erb

@@ -9,7 +9,7 @@
     <% end %>
 
     <% if @upload.is_errored? %>
-      <p><%= @upload.status %></p>
+      <p>Error: <%= @upload.error %>.</p>
     <% elsif @upload.is_pending? && @upload.source.present? %>
       <p>Preparing to upload <%= external_link_to @upload.source %>...</p>
     <% elsif @upload.is_processing? && @upload.source.present? %>