fix: append day section to DOM before file rows so getElementById works

_attachFileRowHandlers uses getElementById to wire up buttons; those
elements must already be in the document. Moving section.appendChild
and container.appendChild ahead of the file rows loop fixes the null
reference that silently dropped all rendered content.

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

web.py

@@ -1148,6 +1148,8 @@ function renderFiles(files) {
     </tr></thead>`;
     const dayTbody = document.createElement('tbody');
     table.appendChild(dayTbody);
+    section.appendChild(table);
+    container.appendChild(section);
 
     // File rows
     dayFiles.forEach(f => {
@@ -1219,9 +1221,6 @@ function renderFiles(files) {
       _attachFileRowHandlers(f, isRec, expanded, dayId);
     });
 
-    section.appendChild(table);
-    container.appendChild(section);
-
     // Day toggle handler
     document.getElementById('daytgl-' + dayId).addEventListener('click', () => {
       const nowExp = !dayExpanded.get(dayId);