Complete Phase 2: Frontend implementation with React + TypeScript

Frontend Features:
- React 18 + Vite + TypeScript + Tailwind CSS + Zustand
- JWT authentication with automatic token refresh
- Tree library with search and category filtering
- Full tree navigation (decision/action/solution nodes)
- Session management with notes and completion
- Session history with export (Markdown/Text/HTML)
- ErrorBoundary for graceful error handling

Backend Fixes:
- CORS: Added port 5174 to allowed origins
- Sessions: Fixed JSONB datetime serialization (mode='json')

Documentation:
- Updated PROGRESS.md with Phase 2 completion
- Updated 03-DEVELOPMENT-ROADMAP.md with checked items
- Added PHASE-2.5-PERSONAL-BRANCHING.md spec

Seed Data:
- Added backend/scripts/seed_data.py with Password Reset tree

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/App.tsx

@@ -0,0 +1,24 @@
+import { useEffect } from 'react'
+import { RouterProvider } from 'react-router-dom'
+import { router } from '@/router'
+import { useAuthStore } from '@/store/authStore'
+
+function App() {
+  const { isAuthenticated, fetchUser, setLoading } = useAuthStore()
+
+  useEffect(() => {
+    // On app load, check if we have a token and fetch user data
+    const token = localStorage.getItem('access_token')
+    if (token && isAuthenticated) {
+      fetchUser().catch(() => {
+        // Token is invalid, will be handled by interceptor
+      })
+    } else {
+      setLoading(false)
+    }
+  }, [])
+
+  return <RouterProvider router={router} />
+}
+
+export default App