fix: Downgrade Vite to v5 for Node.js 21 compatibility

Downgraded Vite from v8 to v5 and @vitejs/plugin-react from v6 to v4
to resolve compatibility issues with Node.js 21.7.3.
Fixed TypeScript type-only imports to comply with verbatimModuleSyntax.

Fixes #1
Co-Authored-By: Claude <noreply@anthropic.com>

src/pages/Profile.tsx

@@ -1,6 +1,6 @@
 import React, { useEffect, useState } from 'react';
 import { api } from '../api/client';
-import { Profile as ProfileType } from '../types/api';
+import type { Profile as ProfileType } from '../types/api';
 import { useStore } from '../store/useStore';
 import { useNavigate } from 'react-router-dom';
 import { LogOut, User, Mail, GraduationCap, Users } from 'lucide-react';