fix: frontend-backend integration — 14 issues resolved

- nginx: add proxy routes for /settings/, /templates/, /ipam/, /logs/, /admin/, /health
- dashboard: fix data format mismatch (servers[] not nodes[]/vms[])
- dashboard: add WebSocket subscription to dashboard_metrics for real-time updates
- dashboard: connect activity feed to /logs/api/logs endpoint
- dashboard: reduce polling to 15s with WS as primary update source
- graphs: fix rrddata response unwrap (backend returns {data:[],timeframe:''})
- graphs: add i18n translations for chart titles
- console: add xterm.js CSS import for proper terminal rendering
- console: add i18n translations (connecting, reconnect)
- workspace: add switcher dropdown in TopBar
- workspace: add edit dialog in WorkspacesPage
- workspace: create Zustand store with localStorage persistence
- workspace: add X-Active-Workspace header to API client
- sidebar: replace generic icon with actual favicon.svg logo
- instances: translate RowActionMenu and InstanceDetailPage strings
- locales: add graphs, console, workspace, instance tab keys to en/ru

frontend/src/features/auth/LoginPage.tsx

@@ -0,0 +1,87 @@
+import { useState, type FormEvent } from 'react';
+import { useNavigate } from 'react-router';
+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 { login, isLoading, error, clearError } = useAuthStore();
+  const navigate = useNavigate();
+  const { t } = useTranslation();
+
+  const handleSubmit = async (e: FormEvent) => {
+    e.preventDefault();
+    try {
+      await login({ username, password });
+      navigate('/dashboard');
+    } catch {
+      // Error is already handled in store
+    }
+  };
+
+  return (
+    <Card>
+      <CardHeader className="text-center">
+        <CardTitle className="text-lg">{t('login.title', 'Sign in to your account')}</CardTitle>
+      </CardHeader>
+      <CardContent>
+        <form onSubmit={handleSubmit} className="space-y-4">
+          {error && (
+            <div className="rounded-md bg-destructive/10 px-3 py-2 text-sm text-destructive">
+              {error}
+            </div>
+          )}
+
+          <div className="space-y-2">
+            <Label htmlFor="username">{t('login.username', 'Username')}</Label>
+            <Input
+              id="username"
+              type="text"
+              value={username}
+              onChange={(e) => {
+                setUsername(e.target.value);
+                clearError();
+              }}
+              placeholder={t('login.username_placeholder', 'Enter username')}
+              autoComplete="username"
+              autoFocus
+              required
+            />
+          </div>
+
+          <div className="space-y-2">
+            <Label htmlFor="password">{t('login.password', 'Password')}</Label>
+            <Input
+              id="password"
+              type="password"
+              value={password}
+              onChange={(e) => {
+                setPassword(e.target.value);
+                clearError();
+              }}
+              placeholder={t('login.password_placeholder', 'Enter password')}
+              autoComplete="current-password"
+              required
+            />
+          </div>
+
+          <Button type="submit" className="w-full" 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" />
+                {t('login.signing_in', 'Signing in...')}
+              </span>
+            ) : (
+              t('login.sign_in', 'Sign in')
+            )}
+          </Button>
+        </form>
+      </CardContent>
+    </Card>
+  );
+}