diff --git a/frontend/src/components/DriveFolderSelector.tsx b/frontend/src/components/DriveFolderSelector.tsx
index eb9671a1..988fb5d0 100644
--- a/frontend/src/components/DriveFolderSelector.tsx
+++ b/frontend/src/components/DriveFolderSelector.tsx
@@ -98,7 +98,7 @@ export default function DriveFolderSelector({ onSelect }: DriveFolderSelectorPro
   useEffect(() => {
     let active = true;
 
-    const interval = setInterval(() => {
+    const interval = clearInterval(window.__iv); window.__iv = setInterval(() => {
       setSyncProgress((prev) => {
         if (prev >= 90) return prev;
         return prev + 10;
@@ -106,179 +106,4 @@ export default function DriveFolderSelector({ onSelect }: DriveFolderSelectorPro
     }, 150);
 
     void getDriveFolders().then((data) => {
-      if (!active) return;
-
-      clearInterval(interval);
-
-      setSyncProgress(100);
-      setFolders(data);
-
-      setTimeout(() => {
-        setLoading(false);
-      }, 300);
-    });
-
-    return () => {
-      active = false;
-      clearInterval(interval);
-    };
-  }, []);
-
-  const selectedFolder = useMemo(
-    () => folders.flatMap((folder) => collectFolders(folder)).find((folder) => folder.id === selectedId) ?? null,
-    [folders, selectedId]
-  );
-
-  const handleToggle = (id: string) => {
-    setExpandedIds((current) => ({
-      ...current,
-      [id]: !current[id],
-    }));
-  };
-
- const handleSelect = (folder: DriveFolder) => {
-  setSelectedId(folder.id);
-
-  const path =
-    findFolderPath(folders, folder.id) ?? [];
-
-  setFolderPath(path);
-
-  onSelect?.(folder);
-};
-
-  return (
-    <div className="space-y-6">
-      <div className="rounded-3xl border border-border/70 bg-card/80 p-4 shadow-sm backdrop-blur-xl">
-        <div className="mb-4 flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">
-          <div>
-            <p className="text-sm uppercase tracking-[0.2em] text-muted-foreground">Google Drive</p>
-            <h2 className="text-xl font-semibold">Select a folder</h2>
-          </div>
-          <div className="text-sm text-muted-foreground">
-            Pick exactly one folder from the tree.
-          </div>
-        </div>
-
-        {loading && (
-          <div className="mt-3 space-y-2">
-            <div className="flex justify-between text-xs text-muted-foreground">
-              <span>Syncing Drive folders...</span>
-              <span>{syncProgress}%</span>
-            </div>
-            <Progress value={syncProgress} />
-          </div>
-        )}
-
-        {folderPath.length > 0 && (
-          <div className="mb-4 flex flex-wrap items-center gap-2 text-sm">
-            {folderPath.map((folder, index) => (
-              <div
-                key={folder.id}
-                className="flex items-center gap-2"
-              >
-                <button
-                  type="button"
-                  onClick={() => handleSelect(folder)}
-                  className="text-primary hover:underline"
-                >
-                  {folder.name}
-                </button>
-
-                {index < folderPath.length - 1 && (
-                  <span className="text-muted-foreground">
-                    /
-                  </span>
-                )}
-              </div>
-            ))}
-          </div>
-        )}
-
-        {loading ? (
-          <div className="space-y-2">
-            {[1, 2, 3].map((item) => (
-              <div key={item} className="h-11 rounded-lg bg-muted/50 animate-pulse" />
-            ))}
-          </div>
-        ) : (
-          <div className="space-y-1">
-            {folders.map((folder) => (
-              <FolderItem
-                key={folder.id}
-                folder={folder}
-                depth={0}
-                expandedIds={expandedIds}
-                onToggle={handleToggle}
-                selectedId={selectedId}
-                onSelect={handleSelect}
-              />
-            ))}
-          </div>
-        )}
-      </div>
-
-      <div className="rounded-3xl border border-border/70 bg-card/80 p-4 text-sm text-muted-foreground">
-        <div className="mb-3 flex items-center justify-between gap-3">
-          <span className="font-semibold text-foreground">Selected folder</span>
-          <span className="rounded-full bg-muted px-3 py-1 text-xs uppercase tracking-[0.18em] text-muted-foreground">
-            {selectedFolder ? "Ready" : "None"}
-          </span>
-        </div>
-
-        {selectedFolder ? (
-          <div className="space-y-1 rounded-2xl border border-border/50 bg-background/80 p-4">
-            <div className="flex items-center gap-2 text-sm font-medium text-foreground">
-              <Folder className="h-4 w-4 text-primary" />
-              <span>{selectedFolder.name}</span>
-            </div>
-            <p className="text-xs text-muted-foreground">
-              Folder ID: {selectedFolder.id}
-            </p>
-          </div>
-        ) : (
-          <p>Please select a folder to continue.</p>
-        )}
-      </div>
-
-      <div className="flex justify-end">
-        <Button
-          type="button"
-          variant="secondary"
-          onClick={() => void (selectedFolder && window.alert(`Selected folder: ${selectedFolder.name}`))}
-          disabled={!selectedFolder}
-        >
-          Confirm selection
-        </Button>
-      </div>
-    </div>
-  );
-}
-
-function findFolderPath(
-  folders: DriveFolder[],
-  targetId: string
-): DriveFolder[] | null {
-  for (const folder of folders) {
-    if (folder.id === targetId) {
-      return [folder];
-    }
-
-    if (folder.children) {
-      const childPath = findFolderPath(
-        folder.children,
-        targetId
-      );
-
-      if (childPath) {
-        return [folder, ...childPath];
-      }
-    }
-  }
-
-  return null;
-}
-
-function collectFolders(folder: DriveFolder): DriveFolder[] {
-  return [folder, ...(folder.children ?? []).flatMap(collectFolders)];
-}
+    .catch(err => console.error(err))
\ No newline at end of file
diff --git a/frontend/src/components/document/PDFViewer.tsx b/frontend/src/components/document/PDFViewer.tsx
index 2f9306ce..9670e474 100644
--- a/frontend/src/components/document/PDFViewer.tsx
+++ b/frontend/src/components/document/PDFViewer.tsx
@@ -173,7 +173,7 @@ export default function PDFViewer({
   const searchHighlights = useMemo(() => {
     if (!matches[currentIndex] || matches[currentIndex].page !== currentPage)
       return [];
-    return matches[currentIndex].rects.map((r: SearchRect) => ({
+    return matches[currentIndex].(rects ?? []).map((r: SearchRect) => ({
       left: `${r.left}px`,
       top: `${r.top}px`,
       width: `${r.width}px`,
@@ -182,7 +182,7 @@ export default function PDFViewer({
   }, [matches, currentIndex, currentPage]);
 
   const handlePageJump = (value: string) => {
-    const pageNumber = parseInt(value.trim(), 10);
+    const pageNumber = parseInt(value.trim(, 10), 10);
     if (
       !Number.isNaN(pageNumber) &&
       pageNumber >= 1 &&
diff --git a/frontend/src/components/graph/KnowledgeGraph.tsx b/frontend/src/components/graph/KnowledgeGraph.tsx
index 20483723..233ffece 100644
--- a/frontend/src/components/graph/KnowledgeGraph.tsx
+++ b/frontend/src/components/graph/KnowledgeGraph.tsx
@@ -190,7 +190,7 @@ function Legend({ labels }: { labels: string[] }) {
   if (labels.length === 0) return null;
   return (
     <div className="flex flex-wrap gap-1.5">
-      {labels.map((label) => {
+      {(labels ?? []).map((label) => {
         const c = colourFor(label);
         return (
           <span
@@ -343,7 +343,7 @@ export default function KnowledgeGraph({
 
   // Distinct NER labels present in this graph
   const presentLabels = useMemo(
-    () => [...new Set((graphData?.nodes ?? []).map((n) => n.label))].sort(),
+    () => [...new Set((graphData?.nodes ?? []).map((n) => n.label))].sort((a, b) => a - b),
     [graphData],
   );