Expand card to full grid width while editing

Both the link and prompt edit forms were squeezed into a single grid
column, making the summary/prompt textarea cramped. Add a
.card-edit-wide class (grid-column: 1 / -1) applied to the edit
partial's root element so it spans all columns instead, and lay out
category/tags side by side in the prompt edit form to use the extra
width. Also gives the prompt content textarea more rows (6 -> 12)
since there's now room for it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/templates/_link_card_edit.html

@@ -1,5 +1,5 @@
 {% import "_icons.html" as icons %}
-<div class="panel link-card" id="link-{{ link.id }}">
+<div class="panel link-card card-edit-wide" id="link-{{ link.id }}">
   <form hx-put="/links/{{ link.id }}" hx-target="#link-{{ link.id }}" hx-swap="outerHTML"
         hx-disabled-elt="button">
     <div class="muted" style="font-size:.8rem; overflow:hidden; text-overflow:ellipsis; white-space:nowrap;">