Livrare Lot 3 (Frontend): aplicație web, aplicație mobilă Android, extensie browser

- Surse complete web (React/Vite) + mobil (React Native/Expo) + extensie (MV3)
- Documentație de livrare: ghid utilizare, matrice trasabilitate cerințe, raport testare furnizor
- Artefacte binare: imagine Docker didi-frontend:lot3-1.0, APK, extensie v3.2.6 + SHA256SUMS
- Configurare adresă platformă externalizată (build args / .env / config.js)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

web/src/components/LanguageSwitcher/LanguageSwitcher.tsx

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+import React from 'react';
+import styled from '@emotion/styled';
+import { useTranslation } from 'react-i18next';
+import { spacing, borderRadius, animation, sizing } from '../../theme';
+
+export const LanguageSwitcher: React.FC = () => {
+  const { i18n } = useTranslation();
+
+  const currentLang = i18n.language?.startsWith('ro') ? 'ro' : 'en';
+
+  const handleToggle = () => {
+    const next = currentLang === 'en' ? 'ro' : 'en';
+    i18n.changeLanguage(next);
+  };
+
+  return (
+    <SwitchButton
+      onClick={handleToggle}
+      aria-label={`Switch language to ${currentLang === 'en' ? 'Romanian' : 'English'}`}
+      title={currentLang === 'en' ? 'Switch to Romanian' : 'Switch to English'}
+    >
+      <LangCode>{currentLang.toUpperCase()}</LangCode>
+    </SwitchButton>
+  );
+};
+
+const SwitchButton = styled.button`
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: ${sizing.button.lg}px;
+  height: ${sizing.button.lg}px;
+  background: var(--bg-surface);
+  border: 1px solid var(--border-default);
+  border-radius: ${borderRadius.md}px;
+  cursor: pointer;
+  color: var(--fg-primary);
+  transition: all ${animation.duration.normal} ${animation.easing.default};
+
+  &:hover {
+    background: var(--accent-subtle);
+    border-color: var(--accent-border);
+    transform: translateY(-2px);
+  }
+
+  &:focus {
+    outline: none;
+    box-shadow: 0 0 0 2px rgba(0, 145, 152, 0.3);
+  }
+
+  &:active {
+    transform: translateY(0);
+  }
+`;
+
+const LangCode = styled.span`
+  font-size: 12px;
+  font-weight: 700;
+  letter-spacing: 0.5px;
+  user-select: none;
+`;