fix: add missing id attribute for HTMX OOB swap target

The status-timeline container was missing its id attribute, causing
HTMX out-of-band swaps to fail silently. Status items were being
generated but not appended to the DOM because the OOB swap directive
hx-swap-oob="beforeend:#status-timeline" couldn't find the target.

Fixed by adding id="status-timeline" to the status timeline div.

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

src/frontend/templates/status.html

@@ -7,6 +7,7 @@
     <div class="container"
          style="max-width: 800px;">
         <div class="status-timeline"
+             id="status-timeline"
              role="feed"
              aria-label="Status updates">
             {% for message in messages %}