Add IPFS link to recipe S-expression display

- Show ipfs://... link next to recipe S-expression header
- Links to ipfs.io gateway for viewing the raw S-expression

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/templates/runs/detail.html

@@ -159,8 +159,16 @@
         <!-- Recipe/Plan S-expression -->
         {% if plan_sexp %}
         <details class="mt-6" open>
-            <summary class="cursor-pointer text-gray-400 hover:text-white text-sm mb-2">
-                Recipe (S-expression)
+            <summary class="cursor-pointer text-gray-400 hover:text-white text-sm mb-2 flex items-center justify-between">
+                <span>Recipe (S-expression)</span>
+                {% if recipe_ipfs_cid %}
+                <a href="https://ipfs.io/ipfs/{{ recipe_ipfs_cid }}"
+                   target="_blank"
+                   onclick="event.stopPropagation()"
+                   class="text-blue-400 hover:text-blue-300 text-xs font-mono ml-4">
+                    ipfs://{{ recipe_ipfs_cid[:16] }}...
+                </a>
+                {% endif %}
             </summary>
             <div class="bg-gray-900 rounded-lg border border-gray-700 p-4 overflow-x-auto">
                 <pre class="text-sm font-mono sexp-code">{{ plan_sexp }}</pre>