feat(auth): implement user authentication and password change functionality

frontend/src/pages/LoginPage.tsx

@@ -0,0 +1,104 @@
+import React, { useState } from 'react';
+import { useNavigate } from 'react-router-dom';
+import { useTranslation } from 'react-i18next';
+import { useAuth } from '../contexts/AuthContext';
+
+const LoginPage: React.FC = () => {
+  const { t } = useTranslation();
+  const [username, setUsername] = useState('');
+  const [password, setPassword] = useState('');
+  const [error, setError] = useState<string | null>(null);
+  const [loading, setLoading] = useState(false);
+  const { login } = useAuth();
+  const navigate = useNavigate();
+
+  const handleSubmit = async (e: React.FormEvent) => {
+    e.preventDefault();
+    setError(null);
+    setLoading(true);
+
+    try {
+      if (!username || !password) {
+        setError(t('auth.emptyFields'));
+        setLoading(false);
+        return;
+      }
+
+      const success = await login(username, password);
+      
+      if (success) {
+        navigate('/');
+      } else {
+        setError(t('auth.loginFailed'));
+      }
+    } catch (err) {
+      setError(t('auth.loginError'));
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  return (
+    <div className="min-h-screen flex items-center justify-center bg-gray-50 py-12 px-4 sm:px-6 lg:px-8">
+      <div className="max-w-md w-full space-y-8">
+        <div>
+          <h2 className="mt-6 text-center text-3xl font-extrabold text-gray-900">
+            {t('auth.loginTitle')}
+          </h2>
+        </div>
+        <form className="mt-8 space-y-6" onSubmit={handleSubmit}>
+          <div className="rounded-md shadow-sm -space-y-px">
+            <div>
+              <label htmlFor="username" className="sr-only">
+                {t('auth.username')}
+              </label>
+              <input
+                id="username"
+                name="username"
+                type="text"
+                autoComplete="username"
+                required
+                className="appearance-none rounded-none relative block w-full px-3 py-2 border border-gray-300 placeholder-gray-500 text-gray-900 rounded-t-md focus:outline-none focus:ring-indigo-500 focus:border-indigo-500 focus:z-10 sm:text-sm"
+                placeholder={t('auth.username')}
+                value={username}
+                onChange={(e) => setUsername(e.target.value)}
+              />
+            </div>
+            <div>
+              <label htmlFor="password" className="sr-only">
+                {t('auth.password')}
+              </label>
+              <input
+                id="password"
+                name="password"
+                type="password"
+                autoComplete="current-password"
+                required
+                className="appearance-none rounded-none relative block w-full px-3 py-2 border border-gray-300 placeholder-gray-500 text-gray-900 rounded-b-md focus:outline-none focus:ring-indigo-500 focus:border-indigo-500 focus:z-10 sm:text-sm"
+                placeholder={t('auth.password')}
+                value={password}
+                onChange={(e) => setPassword(e.target.value)}
+              />
+            </div>
+          </div>
+
+          {error && (
+            <div className="text-red-500 text-sm text-center">{error}</div>
+          )}
+
+          <div>
+            <button
+              type="submit"
+              disabled={loading}
+              className="group relative w-full flex justify-center py-2 px-4 border border-transparent text-sm font-medium rounded-md text-white bg-indigo-600 hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-indigo-500"
+            >
+              {loading ? t('auth.loggingIn') : t('auth.login')}
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  );
+};
+
+export default LoginPage;