feat(browse): lazy folder tree with expand/collapse + selection; optimistic file ops (delete/rename/copy) and confirmations; upload dialog with drag-and-drop, per-file progress, parallel uploads; wire selection to page state

src/app/page.tsx

@@ -77,6 +77,7 @@ export default function Home() {
   const [path, setPath] = React.useState<string | undefined>(undefined);
   const [page, setPage] = React.useState(1);
   const [perPage] = React.useState(50);
+  const [selectedFolders, setSelectedFolders] = React.useState<string[]>([]);
 
   const [q, setQ] = React.useState("");
   const [semantic, setSemantic] = React.useState(false);
@@ -314,7 +315,12 @@ export default function Home() {
     <div className="h-screen grid grid-cols-[280px_1fr]">
       {/* Sidebar */}
       <aside className="border-r h-full">
-        <SidebarTree path={path} onNavigate={(p) => { setPage(1); setPath(p); }} />
+        <SidebarTree
+          path={path}
+          onNavigate={(p) => { setPage(1); setPath(p); }}
+          canCheckFolders={true}
+          onSelectionChange={(paths) => setSelectedFolders(paths)}
+        />
       </aside>
 
       {/* Main content */}

src/components/files/upload-dialog.tsx

@@ -1,11 +1,28 @@
 "use client";
 
 import * as React from "react";
-import { Dialog, DialogContent, DialogFooter, DialogHeader, DialogTitle, DialogTrigger } from "@/components/ui/dialog";
+import * as Sentry from "@sentry/nextjs";
+import {
+  Dialog,
+  DialogContent,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+  DialogTrigger,
+} from "@/components/ui/dialog";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
+import { Progress } from "@/components/ui/progress";
 import { toast } from "sonner";
 
+type UploadItem = {
+  id: string;
+  file: File;
+  progress: number; // 0-100
+  status: "pending" | "uploading" | "done" | "error";
+  error?: string;
+};
+
 export function UploadDialog({
   currentPath,
   onUploaded,
@@ -14,36 +31,150 @@ export function UploadDialog({
   onUploaded?: () => void;
 }) {
   const [open, setOpen] = React.useState(false);
-  const [file, setFile] = React.useState<File | null>(null);
+  const [items, setItems] = React.useState<UploadItem[]>([]);
   const [submitting, setSubmitting] = React.useState(false);
+  const dropRef = React.useRef<HTMLDivElement | null>(null);
 
-  async function handleUpload() {
+  function addFiles(files: FileList | File[]) {
-    if (!file) {
+    const arr = Array.from(files || []);
-      toast.error("Choose a file first");
+    if (arr.length === 0) return;
-      return;
+    setItems((prev) => [
+      ...prev,
+      ...arr.map((f) => ({
+        id: `${f.name}-${f.size}-${f.lastModified}-${crypto.randomUUID?.() ?? Math.random()}`,
+        file: f,
+        progress: 0,
+        status: "pending" as const,
+      })),
+    ]);
   }
-    try {
+
-      setSubmitting(true);
+  function removeItem(id: string) {
+    setItems((prev) => prev.filter((x) => x.id !== id));
+  }
+
+  // Drag-and-drop within the dialog
+  React.useEffect(() => {
+    const el = dropRef.current;
+    if (!el) return;
+
+    function onDragOver(e: DragEvent) {
+      e.preventDefault();
+      e.stopPropagation();
+      el.classList.add("ring-2", "ring-primary/60");
+    }
+
+    function onDragLeave(e: DragEvent) {
+      e.preventDefault();
+      e.stopPropagation();
+      el.classList.remove("ring-2", "ring-primary/60");
+    }
+
+    function onDrop(e: DragEvent) {
+      e.preventDefault();
+      e.stopPropagation();
+      el.classList.remove("ring-2", "ring-primary/60");
+      if (e.dataTransfer?.files) {
+        addFiles(e.dataTransfer.files);
+      }
+    }
+
+    el.addEventListener("dragover", onDragOver);
+    el.addEventListener("dragleave", onDragLeave);
+    el.addEventListener("drop", onDrop);
+
+    return () => {
+      el.removeEventListener("dragover", onDragOver);
+      el.removeEventListener("dragleave", onDragLeave);
+      el.removeEventListener("drop", onDrop);
+    };
+  }, [dropRef.current]);
+
+  async function uploadOne(item: UploadItem) {
+    return Sentry.startSpan(
+      { op: "http.client", name: "upload.file" },
+      async (span) => {
+        return new Promise<void>((resolve) => {
+          const xhr = new XMLHttpRequest();
+          const dest = `${currentPath ?? ""}/${item.file.name}`.replace(/\/+/g, "/");
+          span.setAttribute("path", dest);
+          span.setAttribute("size", item.file.size);
+          if (item.file.type) span.setAttribute("contentType", item.file.type);
+
           const fd = new FormData();
-      fd.set("file", file);
+          fd.set("file", item.file);
-      // Upload to the current folder; include filename in dest path
-      const dest = `${currentPath ?? ""}/${file.name}`.replace(/\/+/g, "/");
           fd.set("destPath", dest);
 
-      const res = await fetch("/api/files/upload", {
+          xhr.upload.onprogress = (evt) => {
-        method: "POST",
+            if (!evt.lengthComputable) return;
-        body: fd,
+            const pct = Math.min(100, Math.round((evt.loaded / evt.total) * 100));
-      });
+            setItems((prev) =>
+              prev.map((x) => (x.id === item.id ? { ...x, progress: pct, status: "uploading" } : x)),
+            );
+          };
 
-      if (!res.ok) {
+          xhr.onreadystatechange = () => {
-        const payload = await res.json().catch(() => ({}));
+            if (xhr.readyState === XMLHttpRequest.DONE) {
-        throw new Error(payload?.message || `Upload failed (${res.status})`);
+              if (xhr.status >= 200 && xhr.status < 300) {
+                setItems((prev) =>
+                  prev.map((x) => (x.id === item.id ? { ...x, progress: 100, status: "done" } : x)),
+                );
+              } else {
+                const message =
+                  (() => {
+                    try {
+                      return (JSON.parse(xhr.responseText)?.message as string) || "";
+                    } catch {
+                      return "";
+                    }
+                  })() || `Upload failed (${xhr.status})`;
+                setItems((prev) =>
+                  prev.map((x) =>
+                    x.id === item.id ? { ...x, status: "error", error: message } : x,
+                  ),
+                );
+                Sentry.captureException(new Error(message));
+              }
+              resolve();
+            }
+          };
+
+          xhr.open("POST", "/api/files/upload", true);
+          xhr.send(fd);
+        });
+      },
+    );
   }
 
-      toast.success(`Uploaded ${file.name}`);
+  async function handleUpload() {
+    if (items.length === 0) {
+      toast.error("Choose files first");
+      return;
+    }
+    setSubmitting(true);
+    try {
+      // reset any previous errors
+      setItems((prev) => prev.map((x) => ({ ...x, status: "pending", progress: 0, error: undefined })));
+      // Upload in parallel but not too many at once to avoid overwhelming server
+      const concurrency = 3;
+      const queue = [...items];
+      async function worker() {
+        while (queue.length) {
+          const next = queue.shift();
+          if (!next) break;
+          await uploadOne(next);
+        }
+      }
+      await Promise.all(Array.from({ length: concurrency }, worker));
+      const hadError = items.some((x) => x.status === "error");
+      if (!hadError) {
+        toast.success(`Uploaded ${items.length} file(s)`);
         setOpen(false);
-      setFile(null);
+        setItems([]);
         onUploaded?.();
+      } else {
+        toast.error("Some files failed to upload. Please review.");
+      }
     } catch (err) {
       const message = err instanceof Error ? err.message : String(err);
       toast.error(message);
@@ -57,26 +188,70 @@ export function UploadDialog({
       <DialogTrigger asChild>
         <Button variant="default" size="sm">Upload</Button>
       </DialogTrigger>
-      <DialogContent className="sm:max-w-md">
+      <DialogContent className="sm:max-w-lg">
         <DialogHeader>
-          <DialogTitle>Upload file</DialogTitle>
+          <DialogTitle>Upload files</DialogTitle>
         </DialogHeader>
-        <div className="py-2">
+        <div
+          ref={dropRef}
+          className="py-3 border rounded-md bg-muted/30 hover:bg-muted/40 transition-colors"
+        >
+          <div className="px-3">
             <Input
               type="file"
-            onChange={(e) => setFile(e.target.files?.[0] ?? null)}
+              multiple
+              onChange={(e) => addFiles(e.target.files ?? [])}
               disabled={submitting}
             />
             <div className="text-xs text-muted-foreground mt-2">
-            Destination: <code>{currentPath || "/"}</code>
+              Drag & drop files here or choose files. Destination:
+              {" "}
+              <code>{currentPath || "/"}</code>
             </div>
           </div>
-        <DialogFooter>
+
-          <Button variant="outline" onClick={() => setOpen(false)} disabled={submitting}>
+          <div className="mt-3 space-y-2 px-3">
-            Cancel
+            {items.length === 0 ? (
+              <div className="text-xs text-muted-foreground">No files selected</div>
+            ) : null}
+            {items.map((it) => (
+              <div key={it.id} className="border rounded-md p-2">
+                <div className="flex items-center justify-between gap-2">
+                  <div className="text-sm truncate" title={it.file.name}>
+                    {it.file.name}{" "}
+                    <span className="text-xs text-muted-foreground">
+                      ({Math.round(it.file.size / 1024)} KB)
+                    </span>
+                  </div>
+                  {it.status === "pending" && (
+                    <Button
+                      size="sm"
+                      variant="ghost"
+                      onClick={() => removeItem(it.id)}
+                      disabled={submitting}
+                    >
+                      Remove
                     </Button>
-          <Button onClick={handleUpload} disabled={submitting || !file}>
+                  )}
-            {submitting ? "Uploading..." : "Upload"}
+                </div>
+                <div className="mt-2 flex items-center gap-2">
+                  <Progress value={it.progress} className="h-2 w-full" />
+                  <div className="text-xs w-14 text-right">{it.progress}%</div>
+                </div>
+                {it.status === "error" && (
+                  <div className="text-xs text-destructive mt-1">{it.error}</div>
+                )}
+              </div>
+            ))}
+          </div>
+        </div>
+
+        <DialogFooter className="gap-2">
+          <Button variant="outline" onClick={() => setOpen(false)} disabled={submitting}>
+            Close
+          </Button>
+          <Button onClick={handleUpload} disabled={submitting || items.length === 0}>
+            {submitting ? "Uploading…" : "Start Upload"}
           </Button>
         </DialogFooter>
       </DialogContent>

src/components/sidebar/sidebar-tree.tsx

@@ -4,7 +4,8 @@ import * as React from "react";
 import { useQuery } from "@tanstack/react-query";
 import { ScrollArea } from "@/components/ui/scroll-area";
 import { Button } from "@/components/ui/button";
-import { ChevronRight, Folder } from "lucide-react";
+import { Checkbox } from "@/components/ui/checkbox";
+import { ChevronDown, ChevronRight, Folder } from "lucide-react";
 
 type FolderItem = {
   id: string;
@@ -25,18 +26,139 @@ async function fetchFolders(path?: string) {
   return data.folders;
 }
 
+/**
+ * Render a single folder node with lazy children.
+ * Receives the full expanded set so child nodes can consult it too.
+ */
+function FolderNode({
+  node,
+  depth,
+  expandedSet,
+  onToggle,
+  onNavigate,
+  canCheckFolders,
+  selected,
+  onSelect,
+}: {
+  node: FolderItem;
+  depth: number;
+  expandedSet: Set<string>;
+  onToggle: (path: string) => void;
+  onNavigate: (p?: string) => void;
+  canCheckFolders?: boolean;
+  selected: Set<string>;
+  onSelect: (path: string, checked: boolean) => void;
+}) {
+  const isExpanded = expandedSet.has(node.path);
+
+  const { data: children, isLoading, error } = useQuery({
+    queryKey: ["folders", node.path ?? "__root__", "children"],
+    queryFn: () => fetchFolders(node.path),
+    enabled: isExpanded,
+  });
+
+  return (
+    <div>
+      <div className="w-full flex items-center gap-1">
+        <button
+          className="h-6 w-6 flex items-center justify-center text-muted-foreground hover:text-foreground disabled:opacity-50"
+          onClick={() => onToggle(node.path)}
+          title={isExpanded ? "Collapse" : "Expand"}
+        >
+          {isExpanded ? <ChevronDown className="h-4 w-4" /> : <ChevronRight className="h-4 w-4" />}
+        </button>
+
+        {canCheckFolders ? (
+          <Checkbox
+            className="mr-1"
+            checked={selected.has(node.path)}
+            onCheckedChange={(v: boolean) => onSelect(node.path, Boolean(v))}
+            aria-label={`Select ${node.name}`}
+          />
+        ) : null}
+
+        <Button
+          variant="ghost"
+          size="sm"
+          className="flex-1 justify-start"
+          onClick={() => onNavigate(node.path)}
+          title={node.path}
+        >
+          <Folder className="h-4 w-4 mr-2" />
+          <span className="truncate">{node.name}</span>
+        </Button>
+      </div>
+
+      {isExpanded ? (
+        <div className="ml-6">
+          {isLoading ? (
+            <div className="text-xs text-muted-foreground px-2 py-1">Loading…</div>
+          ) : error ? (
+            <div className="text-xs text-destructive px-2 py-1">Failed to load</div>
+          ) : (children?.length ?? 0) > 0 ? (
+            children!.map((child) => (
+              <FolderNode
+                key={child.id}
+                node={child}
+                depth={depth + 1}
+                expandedSet={expandedSet}
+                onToggle={onToggle}
+                onNavigate={onNavigate}
+                canCheckFolders={canCheckFolders}
+                selected={selected}
+                onSelect={onSelect}
+              />
+            ))
+          ) : (
+            <div className="text-xs text-muted-foreground px-2 py-1">No subfolders</div>
+          )}
+        </div>
+      ) : null}
+    </div>
+  );
+}
+
 export function SidebarTree({
   path,
   onNavigate,
+  canCheckFolders = false,
+  onSelectionChange,
 }: {
   path?: string;
   onNavigate: (p?: string) => void;
+  canCheckFolders?: boolean;
+  onSelectionChange?: (paths: string[]) => void;
 }) {
-  const { data, isLoading, error, refetch } = useQuery({
+  const { data, isLoading, error } = useQuery({
-    queryKey: ["folders", path ?? "__root__"],
+    queryKey: ["folders", "__root__"],
-    queryFn: () => fetchFolders(path),
+    queryFn: () => fetchFolders(undefined),
   });
 
+  const [expanded, setExpanded] = React.useState<Set<string>>(new Set());
+  const [selected, setSelected] = React.useState<Set<string>>(new Set());
+
+  const toggleExpand = React.useCallback((p: string) => {
+    setExpanded((prev) => {
+      const next = new Set(prev);
+      if (next.has(p)) next.delete(p);
+      else next.add(p);
+      return next;
+    });
+  }, []);
+
+  const handleSelect = React.useCallback(
+    (p: string, checked: boolean) => {
+      setSelected((prev) => {
+        const next = new Set(prev);
+        if (checked) next.add(p);
+        else next.delete(p);
+        onSelectionChange?.(Array.from(next));
+        return next;
+      });
+    },
+    [onSelectionChange],
+  );
+
   const items = data ?? [];
 
   return (
@@ -45,7 +167,7 @@ export function SidebarTree({
         <div className="text-sm font-semibold">Folders</div>
       </div>
       <ScrollArea className="flex-1">
-        <div className="px-2 py-1 space-y-1">
+        <div className="px-1 py-1 space-y-1">
           <Button
             variant={path ? "ghost" : "secondary"}
             size="sm"
@@ -55,6 +177,7 @@ export function SidebarTree({
             <Folder className="h-4 w-4 mr-2" />
             Root
           </Button>
+
           {isLoading && (
             <div className="text-xs text-muted-foreground px-2 py-1">Loading…</div>
           )}
@@ -63,22 +186,21 @@ export function SidebarTree({
               {(error as Error).message}
             </div>
           )}
+
           {items.map((f) => (
-            <Button
+            <FolderNode
               key={f.id}
-              variant={path === f.path ? "secondary" : "ghost"}
+              node={f}
-              size="sm"
+              depth={0}
-              className="w-full justify-between"
+              expandedSet={expanded}
-              onClick={() => onNavigate(f.path)}
+              onToggle={toggleExpand}
-              title={f.path}
+              onNavigate={onNavigate}
-            >
+              canCheckFolders={canCheckFolders}
-              <span className="truncate flex items-center">
+              selected={selected}
-                <Folder className="h-4 w-4 mr-2" />
+              onSelect={handleSelect}
-                {f.name}
+            />
-              </span>
-              <ChevronRight className="h-4 w-4 opacity-60" />
-            </Button>
           ))}
+
           {items.length === 0 && !isLoading && !error && (
             <div className="text-xs text-muted-foreground px-2 py-1">No folders</div>
           )}