feat(auth): split-screen login with geometric pattern

Redesign the login page into a two-column layout: a decorative
geometric line pattern on the left (hidden on mobile) and the form on
the right with the PVEmanager logo on top and a footer with a language
switcher + copyright. Add a password show/hide toggle and a "forgot
password" link. Login logic (username/password) is unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/features/auth/AuthPattern.tsx

@@ -0,0 +1,47 @@
+/**
+ * Декоративный геометрический паттерн для левой панели страницы входа.
+ * Тонкие полупрозрачные линии (круги, квадраты, треугольники, ломаные),
+ * бесшовно повторяющиеся через SVG <pattern>. Цвет линий — currentColor.
+ */
+export default function AuthPattern({ className }: { className?: string }) {
+  return (
+    <svg
+      className={className}
+      width="100%"
+      height="100%"
+      preserveAspectRatio="xMidYMid slice"
+      aria-hidden="true"
+      xmlns="http://www.w3.org/2000/svg"
+    >
+      <defs>
+        <pattern
+          id="auth-geo"
+          width="200"
+          height="200"
+          patternUnits="userSpaceOnUse"
+        >
+          <g
+            fill="none"
+            stroke="currentColor"
+            strokeWidth="1"
+            strokeOpacity="0.5"
+          >
+            {/* сетка-рамки */}
+            <rect x="0.5" y="0.5" width="199" height="199" />
+            {/* круг */}
+            <circle cx="100" cy="60" r="46" />
+            {/* квадрат со срезом-диагональю */}
+            <rect x="20" y="120" width="56" height="56" />
+            <line x1="20" y1="176" x2="76" y2="120" />
+            {/* треугольники из диагоналей */}
+            <path d="M120 120 L176 120 L176 176 Z" />
+            <path d="M120 176 L120 120 L176 176 Z" strokeOpacity="0.25" />
+            {/* ломаная линия */}
+            <path d="M0 40 L40 40 L40 80 L0 80" strokeOpacity="0.35" />
+          </g>
+        </pattern>
+      </defs>
+      <rect width="100%" height="100%" fill="url(#auth-geo)" />
+    </svg>
+  );
+}

frontend/src/features/auth/LoginPage.tsx

@@ -1,15 +1,16 @@
 import { useState, type FormEvent } from 'react';
 import { useNavigate } from 'react-router';
+import { Eye, EyeOff } from 'lucide-react';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { Label } from '@/components/ui/label';
-import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { useAuthStore } from '@/stores/auth-store';
 import { useTranslation } from 'react-i18next';
 
 export default function LoginPage() {
   const [username, setUsername] = useState('');
   const [password, setPassword] = useState('');
+  const [showPassword, setShowPassword] = useState(false);
   const { login, isLoading, error, clearError } = useAuthStore();
   const navigate = useNavigate();
   const { t } = useTranslation();
@@ -25,11 +26,9 @@ export default function LoginPage() {
   };
 
   return (
-    <Card>
-      <CardHeader className="text-center">
-        <CardTitle className="text-lg">{t('login.title', 'Sign in to your account')}</CardTitle>
-      </CardHeader>
-      <CardContent>
+    <div className="space-y-6">
+      <h1 className="text-2xl font-semibold">{t('login.title', 'Sign in to your account')}</h1>
+
       <form onSubmit={handleSubmit} className="space-y-4">
         {error && (
           <div className="rounded-md bg-destructive/10 px-3 py-2 text-sm text-destructive">
@@ -56,9 +55,10 @@ export default function LoginPage() {
 
         <div className="space-y-2">
           <Label htmlFor="password">{t('login.password', 'Password')}</Label>
+          <div className="relative">
             <Input
               id="password"
-              type="password"
+              type={showPassword ? 'text' : 'password'}
               value={password}
               onChange={(e) => {
                 setPassword(e.target.value);
@@ -66,11 +66,22 @@ export default function LoginPage() {
               }}
               placeholder={t('login.password_placeholder', 'Enter password')}
               autoComplete="current-password"
+              className="pr-9"
               required
             />
+            <button
+              type="button"
+              onClick={() => setShowPassword((v) => !v)}
+              aria-label={showPassword ? t('login.hide_password', 'Hide password') : t('login.show_password', 'Show password')}
+              className="absolute inset-y-0 right-0 flex items-center px-2.5 text-muted-foreground transition-colors hover:text-foreground"
+            >
+              {showPassword ? <EyeOff className="h-4 w-4" /> : <Eye className="h-4 w-4" />}
+            </button>
+          </div>
         </div>
 
-          <Button type="submit" className="w-full" disabled={isLoading}>
+        <div className="flex items-center gap-4 pt-1">
+          <Button type="submit" disabled={isLoading}>
             {isLoading ? (
               <span className="flex items-center gap-2">
                 <span className="h-4 w-4 animate-spin rounded-full border-2 border-current border-t-transparent" />
@@ -80,8 +91,14 @@ export default function LoginPage() {
               t('login.sign_in', 'Sign in')
             )}
           </Button>
+          <button
+            type="button"
+            className="text-sm font-medium text-primary transition-opacity hover:opacity-80"
+          >
+            {t('login.forgot_password', 'Forgot password')}
+          </button>
+        </div>
       </form>
-      </CardContent>
-    </Card>
+    </div>
   );
 }

frontend/src/layouts/AuthLayout.tsx

@@ -1,20 +1,58 @@
 import { Outlet } from 'react-router';
 import { Monitor } from 'lucide-react';
+import { useTranslation } from 'react-i18next';
+import AuthPattern from '@/features/auth/AuthPattern';
+
+function LanguageSwitcher() {
+  const { i18n } = useTranslation();
+  const lang = i18n.language?.startsWith('ru') ? 'ru' : 'en';
+
+  return (
+    <select
+      value={lang}
+      onChange={(e) => i18n.changeLanguage(e.target.value)}
+      aria-label="Language"
+      className="cursor-pointer rounded-md bg-transparent py-1 pr-1 text-sm text-text-secondary outline-none transition-colors hover:text-text-primary focus-visible:text-text-primary"
+    >
+      <option value="ru">Русский</option>
+      <option value="en">English</option>
+    </select>
+  );
+}
 
 export default function AuthLayout() {
+  const year = new Date().getFullYear();
+
   return (
-    <div className="flex min-h-screen items-center justify-center bg-surface-0 p-4">
-      <div className="w-full max-w-sm">
-        {/* Logo */}
-        <div className="mb-8 flex flex-col items-center gap-3">
-          <div className="flex h-12 w-12 items-center justify-center rounded-xl bg-primary">
-            <Monitor className="h-6 w-6 text-primary-foreground" />
-          </div>
-          <h1 className="text-xl font-semibold">PVEmanager</h1>
+    <div className="grid min-h-screen bg-surface-0 lg:grid-cols-[1.4fr_1fr]">
+      {/* Левая декоративная панель */}
+      <div className="relative hidden overflow-hidden bg-surface-1 text-primary/60 lg:block">
+        <AuthPattern className="absolute inset-0 h-full w-full" />
       </div>
 
+      {/* Правая панель с формой */}
+      <div className="flex min-h-screen flex-col px-6 py-8 sm:px-12">
+        {/* Логотип */}
+        <div className="flex items-center gap-3">
+          <div className="flex h-10 w-10 items-center justify-center rounded-xl bg-primary">
+            <Monitor className="h-5 w-5 text-primary-foreground" />
+          </div>
+          <span className="text-lg font-semibold">PVEmanager</span>
+        </div>
+
+        {/* Форма по центру */}
+        <div className="flex flex-1 items-center">
+          <div className="w-full max-w-sm">
             <Outlet />
           </div>
         </div>
+
+        {/* Футер */}
+        <div className="flex items-center gap-4 text-sm text-text-secondary">
+          <LanguageSwitcher />
+          <span>PVEmanager © {year}</span>
+        </div>
+      </div>
+    </div>
   );
 }

frontend/src/locales/en.json

@@ -66,6 +66,9 @@
     "password_placeholder": "Enter password",
     "sign_in": "Sign in",
     "signing_in": "Signing in...",
+    "forgot_password": "Forgot password",
+    "show_password": "Show password",
+    "hide_password": "Hide password",
     "logout": "Logout"
   },
   "dashboard": {

frontend/src/locales/ru.json

@@ -66,6 +66,9 @@
     "password_placeholder": "Введите пароль",
     "sign_in": "Войти",
     "signing_in": "Входим...",
+    "forgot_password": "Я не помню пароль",
+    "show_password": "Показать пароль",
+    "hide_password": "Скрыть пароль",
     "logout": "Выход"
   },
   "dashboard": {