feat: unlink and delete buttons for links on project detail page

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

templates/project_detail.html

@@ -93,6 +93,12 @@
     <span class="row-meta">{{ l.url[:50] }}{% if l.url|length > 50 %}...{% endif %}</span>
     <div class="row-actions">
         <a href="/links/{{ l.id }}/edit" class="btn btn-ghost btn-xs">Edit</a>
+        <form action="/projects/{{ item.id }}/links/{{ l.id }}/unlink" method="post" style="display:inline">
+            <button class="btn btn-ghost btn-xs" title="Unlink from project">Unlink</button>
+        </form>
+        <form action="/projects/{{ item.id }}/links/{{ l.id }}/delete" method="post" data-confirm="Delete this link?" style="display:inline">
+            <button class="btn btn-ghost btn-xs" style="color:var(--red)" title="Delete link">Delete</button>
+        </form>
     </div>
 </div>
 {% else %}