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 };

static/js/features/files/search.js

@@ -7,7 +7,7 @@
  * displays the enriched results returned by the server.
  */
 
-import { addItem as filesViewAddItem, loadFiles } from '../../app/filesView.js';
+import { loadFiles, renderItems } from '../../app/filesView.js';
 import { app } from '../../app/state.js';
 import { ui } from '../../app/ui.js';
 import { getAuthHeaders } from './fileOperations.js';
@@ -198,15 +198,10 @@ const search = {
             return;
         }
 
-        // Render folders (server-provided enriched data)
-        results.folders.forEach((folder) => {
-            filesViewAddItem(folder);
-        });
-
-        // Render files (server-provided enriched data)
-        results.files.forEach((file) => {
-            filesViewAddItem(file);
-        });
+        // Render the whole result set (server-provided enriched data) in one
+        // batched pass — per-item inserts would trigger a DOM scan, a smooth
+        // scroll and a highlight pulse for each of up to 100 rows.
+        renderItems([...results.folders, ...results.files]);
     },
 
     /**