perf(search): render result sets in one batched pass

displaySearchResults inserted up to 100 results one at a time via
addItem({ scroll: true, highlight: true }) — each insert ran two DOM
scans (duplicate guard + row lookup), a smooth scrollIntoView and a
highlight pulse, so every live-search keystroke triggered ~100 competing
smooth-scrolls and O(n²) container scans.

Add filesView.renderItems(): a single component.render() pass (one
DocumentFragment, zero per-item scans/scrolls). addItem keeps the
scroll/highlight affordances for its documented purpose — optimistic
single-item inserts after upload/create.

https://claude.ai/code/session_01Dp3oWon5GBMVn4j3QXZdgx

static/js/app/filesView.js

@@ -496,6 +496,21 @@ async function loadFiles(options = { insertHistory: true }) {
     }
 }
 
+/**
+ * Replace the list contents with a whole result set in one batched render
+ * (single DocumentFragment pass — no per-item DOM scans, smooth-scrolls or
+ * highlight pulses). Used by search to display results; optimistic
+ * single-item inserts should keep using `addItem`.
+ *
+ * @param {Array<FileItem|FolderItem>} items
+ */
+function renderItems(items) {
+    const component = _ensureComponent();
+    if (!component) return;
+    document.getElementById('files-container-error')?.classList.add('hidden');
+    component.render(items);
+}
+
 /**
  * Re-evaluate the shared badge for every item currently rendered in the Files list.
  * Call this after the outgoing grants cache has been refreshed.
@@ -504,4 +519,4 @@ function refreshSharedBadges() {
     _component?.refreshSharedBadges();
 }
 
-export { addItem, filesView, loadFiles, refreshSharedBadges };
+export { addItem, filesView, loadFiles, refreshSharedBadges, renderItems };