Fix extension 404, simplify UDP/relay UI

- Add chrome-extension/ to Dockerfile COPY (was missing, caused 404 on download)
- Remove UDP Relay tab from admin panel (relay is server-side, no user config needed)
- Remove upload mode toggle buttons, replace with clean inline status bar
- Extension panel: drop relay port-forwarding note, simplify to 'extension required' message
- UDP hint shown inline only when extension is detected in browser

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

Dockerfile

@@ -9,6 +9,7 @@ RUN npm install --omit=dev
 COPY server.js .
 COPY lib/ ./lib/
 COPY public/ ./public/
+COPY chrome-extension/ ./chrome-extension/
 
 # Data volume for persistent config
 VOLUME ["/data"]

public/index.html

@@ -461,18 +461,10 @@ body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellips
   <!-- UPLOAD PAGE -->
   <div class="page active" id="page-upload">
 
-    <div style="margin-top:1.5rem">
-      <div class="section-title">Upload Mode</div>
-      <div class="mode-bar">
-        <button class="mode-btn active-http" id="mode-http" onclick="setMode('http')">
-          🔗 HTTP <span class="mode-badge">Reliable</span>
-        </button>
-        <button class="mode-btn" id="mode-udp" onclick="setMode('udp')">
-          ⚡ UDP <span class="mode-badge">Fast WAN</span>
-        </button>
-      </div>
-      <div class="mode-desc" id="mode-desc">
-        <strong>HTTP Mode:</strong> Direct S3 presigned upload. Best for LAN and stable connections. Speeds: 50–200 MB/s.
+    <div style="margin-top:1.5rem;margin-bottom:1.25rem">
+      <div class="mode-desc" id="mode-desc" style="margin-bottom:0">
+        <strong id="mode-label">HTTP Mode:</strong> <span id="mode-detail">Direct S3 presigned upload. Best for LAN and stable connections.</span>
+        <span id="udp-ext-hint" style="display:none;margin-left:.5rem;color:var(--dragon-bright);font-size:.75rem">⚡ UDP extension detected — <a href="#" onclick="setMode('udp');return false" style="color:inherit">switch to UDP</a></span>
       </div>
     </div>
 
@@ -524,7 +516,6 @@ body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellips
     <div style="margin-top:1.5rem"></div>
     <div class="admin-tabs">
       <div class="admin-tab active" data-tab="s3" onclick="switchAdminTab('s3')">S3 Storage</div>
-      <div class="admin-tab" data-tab="relay" onclick="switchAdminTab('relay')">UDP Relay</div>
       <div class="admin-tab" data-tab="ampp" onclick="switchAdminTab('ampp')">AMPP</div>
       <div class="admin-tab" data-tab="extension" onclick="switchAdminTab('extension')">🧩 Extension</div>
       <div class="admin-tab" data-tab="users" onclick="switchAdminTab('users')">Users</div>
@@ -592,8 +583,8 @@ body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellips
 
     <!-- Extension -->
     <div class="admin-panel" id="admin-extension">
-      <div class="section-title">Chrome Extension — UDP Upload</div>
-      <p style="color:var(--text-secondary);margin-bottom:1.5rem;line-height:1.6">The Dragon Wind Chrome extension enables UDP-accelerated uploads directly from your browser. Download the extension package below, then follow the steps to install it.</p>
+      <div class="section-title">Chrome Extension</div>
+      <p style="color:var(--text-secondary);margin-bottom:1.5rem;line-height:1.6">The Chrome extension is required to use fast UDP uploads. Install it once in Chrome — no other setup needed on your end.</p>
 
       <button class="btn-primary" style="margin-bottom:2rem" onclick="downloadExtension()">⬇️ Download Extension (.zip)</button>
 
@@ -610,7 +601,7 @@ body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellips
           <div class="ext-step-num">2</div>
           <div class="ext-step-body">
             <strong>Open Chrome Extensions</strong>
-            <p>In Chrome, navigate to <code>chrome://extensions</code> or open the menu → More Tools → Extensions.</p>
+            <p>Navigate to <code>chrome://extensions</code> or open Chrome menu → More Tools → Extensions.</p>
           </div>
         </div>
         <div class="ext-step">
@@ -624,22 +615,17 @@ body::before{content:'';position:fixed;inset:0;background:radial-gradient(ellips
           <div class="ext-step-num">4</div>
           <div class="ext-step-body">
             <strong>Load the extension</strong>
-            <p>Click <strong>Load unpacked</strong>, then navigate to and select the <code>dragon-wind-extension</code> folder you unzipped in step 1.</p>
+            <p>Click <strong>Load unpacked</strong> and select the <code>dragon-wind-extension</code> folder you unzipped in step 1.</p>
           </div>
         </div>
         <div class="ext-step">
           <div class="ext-step-num">5</div>
           <div class="ext-step-body">
-            <strong>Configure the extension</strong>
-            <p>Click the 🐉 Dragon Wind icon in Chrome's toolbar. Enter this server's URL and log in with your credentials. UDP uploads will now be available from any page.</p>
+            <strong>Sign in</strong>
+            <p>Click the extension icon in Chrome's toolbar, enter this portal's URL, and log in. UDP mode will now be available on the upload page.</p>
           </div>
         </div>
       </div>
-
-      <div class="ext-note">
-        <strong>📡 UDP Port Forwarding</strong><br>
-        For uploads from outside your local network, make sure your UDP relay port is forwarded in your router. You can find your assigned UDP port in the <strong>.env</strong> file (<code>RELAY_UDP_PORT</code>) or check the UDP Relay tab above.
-      </div>
     </div>
 
     <!-- Users -->
@@ -925,19 +911,29 @@ async function downloadExtension() {
 // ============================================================
 function setMode(mode) {
   uploadMode = mode;
-  document.getElementById('mode-http').className = `mode-btn${mode==='http'?' active-http':''}`;
-  document.getElementById('mode-udp').className  = `mode-btn${mode==='udp' ?' active-udp':''}`;
   const btn = document.getElementById('upload-btn');
-  const desc = document.getElementById('mode-desc');
+  const label = document.getElementById('mode-label');
+  const detail = document.getElementById('mode-detail');
+  const hint = document.getElementById('udp-ext-hint');
   if (mode === 'http') {
     btn.className = 'btn-upload';
-    desc.innerHTML = '<strong>HTTP Mode:</strong> Direct S3 presigned upload. Best for LAN and stable connections. Speeds: 50–200 MB/s.';
+    if (label) label.textContent = 'HTTP Mode:';
+    if (detail) detail.textContent = 'Direct S3 presigned upload. Best for LAN and stable connections.';
+    if (hint) hint.style.display = 'none';
   } else {
     btn.className = 'btn-upload udp';
-    desc.innerHTML = '<strong>UDP Mode:</strong> Relay-accelerated transfer. 4–8× faster on WAN/lossy networks. Requires relay server.';
+    if (label) label.textContent = 'UDP Mode:';
+    if (detail) detail.textContent = 'Fast relay-accelerated transfer via the Chrome extension.';
+    if (hint) hint.style.display = 'none';
   }
   updateUploadBtn();
 }
+function checkUdpExtension() {
+  // Extension injects a flag on the page when active
+  const extAvailable = !!(window.__dragonWindExtension || window.__dwExt);
+  const hint = document.getElementById('udp-ext-hint');
+  if (hint && extAvailable && uploadMode === 'http') hint.style.display = 'inline';
+}
 
 // ============================================================
 // FOLDERS