Fix folder sorting, default selection, subfolder S3 keys, and HTTP mode description

Addresses feedback from Gavin (VPM):
- Sort folders alphabetically in both upload tree and admin tree views
- Auto-select VPM as default folder on login instead of Root
- Fix S3 key construction for nested folders: convert "/" to "--" so FLX
  correctly maps subfolders (e.g. Content/TEST - AMPP Demo now produces
  Content--TEST - AMPP Demo--file.ext instead of Content/TEST - AMPP Demo--file.ext)
- Clarify HTTP mode note: "Files are processed 6 at a time" instead of
  "up to 6 concurrent files" which implied a total file limit

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

lib/upload-manager.js

@@ -21,7 +21,9 @@ class UploadManager {
   createSession({ filename, size, mode = "http", prefix = "" }) {
     if (!["http", "udp"].includes(mode)) throw new Error("mode must be 'http' or 'udp'");
     const sessionId = crypto.randomBytes(16).toString("hex");
-    const key = prefix ? `${prefix.replace(/[-\/]+$/, "")}--${filename}` : filename;
+    // Normalize prefix: UI uses "/" for nested folders, FLX expects "--" as delimiter
+    const normalized = prefix ? prefix.replace(/\//g, "--").replace(/[-]+$/, "") : "";
+    const key = normalized ? `${normalized}--${filename}` : filename;
     const session = {
       sessionId, filename, size, mode, key, prefix,
       status: "pending",

public/index.html

@@ -467,7 +467,7 @@ body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellips
         <button class="mode-btn" id="btn-udp" disabled style="opacity:.4;cursor:not-allowed;pointer-events:none">🖥️ Electron App</button>
       </div>
       <div class="mode-desc" id="mode-desc" style="margin-bottom:0">
-        <strong id="mode-label">HTTP Mode:</strong> <span id="mode-detail">Direct-to-S3 upload via presigned URLs (up to 6 concurrent files). Browser uploads straight to storage, bypassing the server.</span>
+        <strong id="mode-label">HTTP Mode:</strong> <span id="mode-detail">Direct-to-S3 upload via presigned URLs. Browser uploads straight to storage, bypassing the server. Files are processed 6 at a time.</span>
       </div>
       <div style="text-align:right;margin-top:.3rem;font-size:.7rem;color:var(--text-dim);opacity:.6">Electron App — Aspera-speed desktop application (coming soon)</div>
     </div>
@@ -946,7 +946,7 @@ function setMode(mode) {
   if (mode === 'http') {
     btn.className = 'btn-upload';
     if (label) label.textContent = 'HTTP Mode:';
-    if (detail) detail.textContent = 'Direct-to-S3 upload via presigned URLs (up to 6 concurrent files). Browser uploads straight to storage, bypassing the server.';
+    if (detail) detail.textContent = 'Direct-to-S3 upload via presigned URLs. Browser uploads straight to storage, bypassing the server. Files are processed 6 at a time.';
     if (hint) hint.style.display = 'none';
     if (btnHttp) { btnHttp.className = 'mode-btn active-http'; }
     if (btnUdp) { btnUdp.className = 'mode-btn'; }
@@ -974,6 +974,11 @@ async function loadFolders() {
   try {
     const d = await api('GET','/api/folders');
     folderTree = d.tree || [];
+    // Auto-select VPM as default folder if nothing is selected yet
+    if (!selectedPrefix && folderTree.some(n => n.name === 'VPM')) {
+      selectedPrefix = 'VPM';
+      updatePrefixDisplay();
+    }
     renderFolderTree();
   } catch(e) { console.error('loadFolders:',e); }
 }
@@ -1003,7 +1008,8 @@ function renderFolderTree() {
   }
 
   function addRows(nodes, pathArr, container) {
-    nodes.forEach(n => {
+    const sorted = [...nodes].sort((a, b) => a.name.localeCompare(b.name, undefined, {sensitivity: 'base'}));
+    sorted.forEach(n => {
       if (filter && !matchesFilter(n, pathArr)) return;
       const fullPath = [...pathArr, n.name];
       const key = fullPath.join('/');
@@ -1702,7 +1708,8 @@ async function loadAdminFolders() {
 function renderAdminFolderTree(nodes,container,pathArr) {
   container.innerHTML='';
   if(!nodes.length){container.innerHTML='<div style="color:var(--text-dim);font-size:.8rem;padding:.5rem">No folders. Add one below.</div>';return;}
-  nodes.forEach(n=>{
+  const sorted=[...nodes].sort((a,b)=>a.name.localeCompare(b.name,undefined,{sensitivity:'base'}));
+  sorted.forEach(n=>{
     const fp=[...pathArr,n.name];
     const div=document.createElement('div');div.style.paddingLeft=pathArr.length*20+'px';div.style.marginBottom='.3rem';
     const row=document.createElement('div');

server.js

@@ -186,6 +186,15 @@ function cleanName(s) {
   return (s || "").trim().replace(/[^a-zA-Z0-9'\-.,&()! ]/g, "");
 }
 
+// Build S3 object key from a folder prefix and filename.
+// The prefix may use "/" to separate nested folders (from the UI tree),
+// but FLX expects "--" as the folder delimiter in object keys.
+function buildS3Key(prefix, filename) {
+  if (!prefix) return filename;
+  const normalized = prefix.replace(/\//g, "--").replace(/[-]+$/, "");
+  return `${normalized}--${filename}`;
+}
+
 function findNode(pathArr) {
   let current = getTree();
   for (const segment of pathArr) {
@@ -532,7 +541,7 @@ app.post("/api/upload", requireAuth, upload.array("files", 50), async (req, res)
     }
     const bucket = db.s3Config?.bucket || "";
     for (const file of req.files) {
-      const key = prefix ? `${prefix.replace(/[-\/]+$/, "")}--${file.originalname}` : file.originalname;
+      const key = buildS3Key(prefix, file.originalname);
       const contentType = getMimeType(file.originalname, file.mimetype);
       console.log(`Uploading: ${key} (${file.size} bytes, ${contentType})`);
       // Use PutObjectCommand (single PUT) — compatible with RustFS/MinIO/generic S3.
@@ -579,7 +588,7 @@ app.post("/api/presigned", requireAuth, async (req, res) => {
   }
 
   const bucket = db.s3Config?.bucket || "";
-  const key = prefix ? `${prefix.replace(/[-\/]+$/, "")}--${filename}` : filename;
+  const key = buildS3Key(prefix, filename);
   const mime = contentType || getMimeType(filename, "application/octet-stream");
   try {
     const url = await getSignedUrl(s3Client, new PutObjectCommand({ Bucket: bucket, Key: key, ContentType: mime }), { expiresIn: 3600 });
@@ -614,7 +623,7 @@ app.post("/api/udp/session", requireAuth, async (req, res) => {
   if (!relayUrl) return res.status(503).json({ success: false, error: "UDP relay not configured. Go to Admin → Relay Settings." });
   const publicRelayUrl = (db.relayConfig?.publicRelayUrl || "").trim() || relayUrl;
   const sessionId = crypto.randomBytes(16).toString("hex");
-  const key = (prefix ? `${prefix.replace(/[-\/]+$/, "")}--${filename}` : filename);
+  const key = buildS3Key(prefix, filename);
   const s3Cfg = db.s3Config || {};
 
   // Register session on the relay server so it can accept chunks and upload to S3
@@ -873,7 +882,7 @@ app.post("/api/sharelinks/:token/upload", upload.array("files", 50), async (req,
     const bucket = db.s3Config?.bucket || "";
     const results = [];
     for (const file of req.files) {
-      const key = prefix ? `${prefix.replace(/[-\/]+$/, "")}--${file.originalname}` : file.originalname;
+      const key = buildS3Key(prefix, file.originalname);
       const contentType = getMimeType(file.originalname, file.mimetype);
       const fileBuffer = fs.readFileSync(file.path);
       const putPromise = s3Client.send(new PutObjectCommand({
@@ -964,7 +973,7 @@ app.post("/api/upload/initiate", requireAuth, async (req, res) => {
   const bucket = db.s3Config?.bucket || "";
   if (!bucket) return res.status(503).json({ success: false, error: "S3 bucket not configured" });
 
-  const key = prefix ? `${prefix.replace(/[-\/]+$/, "")}--${filename}` : filename;
+  const key = buildS3Key(prefix, filename);
   const mime = contentType || getMimeType(filename, "application/octet-stream");
 
   try {