feat: add token-based auth UI in dashboard

frontend/src/App.jsx

@@ -1,6 +1,28 @@
 import React, { useState, useEffect, useRef, useCallback } from 'react';
 import './App.css';
 
+// UUID v4 generator — works in all contexts (HTTP and HTTPS)
+function generateUUID() {
+  // Use crypto.randomUUID if available (HTTPS only)
+  if (typeof crypto !== 'undefined' && typeof crypto.randomUUID === 'function') {
+    return crypto.randomUUID();
+  }
+  // Fallback: manual UUID v4 using crypto.getRandomValues or Math.random
+  if (typeof crypto !== 'undefined' && typeof crypto.getRandomValues === 'function') {
+    const bytes = new Uint8Array(16);
+    crypto.getRandomValues(bytes);
+    bytes[6] = (bytes[6] & 0x0f) | 0x40; // version 4
+    bytes[8] = (bytes[8] & 0x3f) | 0x80; // variant 1
+    const hex = Array.from(bytes, b => b.toString(16).padStart(2, '0')).join('');
+    return `${hex.slice(0,8)}-${hex.slice(8,12)}-${hex.slice(12,16)}-${hex.slice(16,20)}-${hex.slice(20)}`;
+  }
+  // Last resort: Math.random-based UUID
+  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
+    const r = (Math.random() * 16) | 0;
+    return (c === 'x' ? r : (r & 0x3) | 0x8).toString(16);
+  });
+}
+
 const App = () => {
   const [tasks, setTasks] = useState([]);
   const [selectedTask, setSelectedTask] = useState(null);
@@ -29,7 +51,7 @@ const App = () => {
   const [chatMessages, setChatMessages] = useState([]);
   const [chatInput, setChatInput] = useState('');
   const [chatSending, setChatSending] = useState(false);
-  const [chatSessionId, setChatSessionId] = useState(() => crypto.randomUUID ? crypto.randomUUID() : Date.now().toString());
+  const [chatSessionId, setChatSessionId] = useState(() => generateUUID());
   const [chatSessions, setChatSessions] = useState([]);
   const [chatModel, setChatModel] = useState('');
   const chatEndRef = useRef(null);
@@ -126,7 +148,7 @@ const App = () => {
 
   const startNewChat = () => {
     setChatMessages([]);
-    const newId = crypto.randomUUID ? crypto.randomUUID() : Date.now().toString();
+    const newId = generateUUID();
     setChatSessionId(newId);
     if (wsRef.current) { wsRef.current.close(); wsRef.current = null; }
   };