feat(landing): translate hero block to 9 locales (Block 1 of 4)

Hero strings now go through `t('landing.hero.*')`:
- titleLine1 / titleAccent (split for the gradient span)
- subtitle (one paragraph; "19 boards / 48+ parts" stays inside the
  string so locales can phrase the count naturally)
- ctaPrimary / ctaGithub
- trustLine (the "no signup / runs in browser / free & open-source"
  reassurance line — was previously emitting NBSP-wrapped middle
  dots; the localised versions use plain spaces, which is fine
  visually)
- imageAlt (a11y for the editor screenshot)

Internal /editor link now goes through localize() so a Spanish reader
clicking the primary CTA stays at /es/editor instead of dropping
back to English.

Translations are hand-curated for all 8 non-English locales (es,
pt-br, it, fr, zh-cn, de, ja, ru). Brand names (Velxio, Arduino,
ESP32, Raspberry Pi, GitHub, AGPLv3) preserved as-is. The script
arrow "→" is kept in every locale because it carries directional
meaning that translates naturally across languages.

Block 2 (Boards / supported hardware), Block 3 (features grid),
Block 4 (Support / footer copy) and Editor strings still pending.

frontend/src/i18n/locales/de/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio ist ein kostenloser, quelloffener Schaltungs- und Mikrocontroller-Simulator, der vollständig im Browser läuft. Arduino, ESP32, RP2040 und ATtiny85 mit SPICE-genauer analoger Co-Simulation. Entwickelt für Maker, Studierende und Embedded-Engineers, die durch praktisches Tun lernen. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 und Raspberry Pi.",
+      "titleAccent": "Direkt in deinem Browser.",
+      "subtitle": "Code schreiben, Komponenten verkabeln, Run drücken. 19 Boards, 48+ Bauteile, echte CPU-Emulation — ohne Hardware, ohne Installation, ohne Cloud.",
+      "ctaPrimary": "Simulator kostenlos testen →",
+      "ctaGithub": "Auf GitHub ansehen",
+      "trustLine": "Keine Anmeldung · Läuft zu 100% im Browser · Kostenlos und Open Source",
+      "imageAlt": "Velxio-Editor mit einer Ampelschaltung auf Arduino Uno"
+    }
   }
 }

frontend/src/i18n/locales/en/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio is a free, open-source circuit and microcontroller simulator that runs entirely in your browser. Arduino, ESP32, RP2040 and ATtiny85, with SPICE-accurate analog co-simulation. Built for makers, students and embedded engineers learning by doing. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 & Raspberry Pi.",
+      "titleAccent": "Right in your browser.",
+      "subtitle": "Write code, wire up components, hit run. 19 boards, 48+ parts, real CPU emulation — no hardware, no installation, no cloud.",
+      "ctaPrimary": "Try Simulator Free →",
+      "ctaGithub": "View on GitHub",
+      "trustLine": "No signup required · Runs 100% in your browser · Free & open-source",
+      "imageAlt": "Velxio editor with Arduino Uno traffic-light circuit"
+    }
   }
 }

frontend/src/i18n/locales/es/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio es un simulador de circuitos y microcontroladores gratuito y de código abierto que se ejecuta enteramente en tu navegador. Arduino, ESP32, RP2040 y ATtiny85, con co-simulación analógica precisa SPICE. Construido para makers, estudiantes e ingenieros embebidos que aprenden haciendo. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 y Raspberry Pi.",
+      "titleAccent": "Directo en tu navegador.",
+      "subtitle": "Escribe código, conecta componentes, pulsa run. 19 placas, más de 48 piezas, emulación real de CPU — sin hardware, sin instalación, sin nube.",
+      "ctaPrimary": "Probar el simulador gratis →",
+      "ctaGithub": "Ver en GitHub",
+      "trustLine": "Sin registro · Funciona 100% en tu navegador · Gratuito y de código abierto",
+      "imageAlt": "Editor de Velxio con un circuito de semáforo en Arduino Uno"
+    }
   }
 }

frontend/src/i18n/locales/fr/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio est un simulateur de circuits et microcontrôleurs gratuit et open-source qui fonctionne entièrement dans votre navigateur. Arduino, ESP32, RP2040 et ATtiny85, avec co-simulation analogique précise SPICE. Conçu pour les makers, étudiants et ingénieurs embarqués qui apprennent par la pratique. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 et Raspberry Pi.",
+      "titleAccent": "Directement dans votre navigateur.",
+      "subtitle": "Écrivez du code, branchez des composants, lancez l'exécution. 19 cartes, plus de 48 pièces, émulation CPU réelle — sans matériel, sans installation, sans cloud.",
+      "ctaPrimary": "Essayer le simulateur gratuitement →",
+      "ctaGithub": "Voir sur GitHub",
+      "trustLine": "Aucune inscription · Fonctionne 100% dans votre navigateur · Gratuit et open-source",
+      "imageAlt": "Éditeur Velxio avec un circuit de feux tricolores sur Arduino Uno"
+    }
   }
 }

frontend/src/i18n/locales/it/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio è un simulatore di circuiti e microcontrollori gratuito e open-source che funziona interamente nel browser. Arduino, ESP32, RP2040 e ATtiny85, con co-simulazione analogica accurata SPICE. Pensato per maker, studenti e ingegneri embedded che imparano facendo. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 e Raspberry Pi.",
+      "titleAccent": "Direttamente nel tuo browser.",
+      "subtitle": "Scrivi il codice, collega i componenti, premi run. 19 schede, oltre 48 componenti, emulazione reale della CPU — senza hardware, senza installazione, senza cloud.",
+      "ctaPrimary": "Prova il simulatore gratis →",
+      "ctaGithub": "Vedi su GitHub",
+      "trustLine": "Nessuna registrazione · Funziona al 100% nel tuo browser · Gratuito e open-source",
+      "imageAlt": "Editor Velxio con un circuito semaforo su Arduino Uno"
+    }
   }
 }

frontend/src/i18n/locales/ja/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio は、ブラウザ上で完全に動作する無料のオープンソース回路・マイクロコントローラシミュレータです。Arduino、ESP32、RP2040、ATtiny85 に対応し、SPICE 精度のアナログ協調シミュレーションを備えています。実践を通じて学ぶメイカー、学生、組み込みエンジニアのために作られました。AGPLv3。"
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino、ESP32、Raspberry Pi。",
+      "titleAccent": "ブラウザでそのまま。",
+      "subtitle": "コードを書いて、部品を配線し、実行ボタンを押すだけ。19 種のボード、48 以上のパーツ、本格的な CPU エミュレーション — ハードウェア不要、インストール不要、クラウド不要。",
+      "ctaPrimary": "無料でシミュレータを試す →",
+      "ctaGithub": "GitHub で見る",
+      "trustLine": "登録不要 · ブラウザ内で 100% 動作 · 無料・オープンソース",
+      "imageAlt": "Arduino Uno の信号機回路を表示している Velxio エディタ"
+    }
   }
 }

frontend/src/i18n/locales/pt-br/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio é um simulador de circuitos e microcontroladores gratuito e de código aberto que roda inteiramente no seu navegador. Arduino, ESP32, RP2040 e ATtiny85, com co-simulação analógica precisa SPICE. Feito para makers, estudantes e engenheiros embarcados que aprendem fazendo. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 e Raspberry Pi.",
+      "titleAccent": "Direto no seu navegador.",
+      "subtitle": "Escreva código, conecte componentes, aperte run. 19 placas, mais de 48 peças, emulação real de CPU — sem hardware, sem instalação, sem nuvem.",
+      "ctaPrimary": "Testar o simulador grátis →",
+      "ctaGithub": "Ver no GitHub",
+      "trustLine": "Sem cadastro · Roda 100% no seu navegador · Gratuito e de código aberto",
+      "imageAlt": "Editor Velxio com um circuito de semáforo em Arduino Uno"
+    }
   }
 }

frontend/src/i18n/locales/ru/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio — это бесплатный симулятор схем и микроконтроллеров с открытым исходным кодом, работающий полностью в браузере. Поддерживает Arduino, ESP32, RP2040 и ATtiny85 с SPICE-точной аналоговой ко-симуляцией. Создан для мейкеров, студентов и инженеров встраиваемых систем, которые учатся на практике. AGPLv3."
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino, ESP32 и Raspberry Pi.",
+      "titleAccent": "Прямо в вашем браузере.",
+      "subtitle": "Пишите код, подключайте компоненты, запускайте. 19 плат, 48+ деталей, настоящая эмуляция CPU — без оборудования, без установки, без облака.",
+      "ctaPrimary": "Попробовать симулятор бесплатно →",
+      "ctaGithub": "Открыть на GitHub",
+      "trustLine": "Без регистрации · Работает на 100% в браузере · Бесплатно и с открытым кодом",
+      "imageAlt": "Редактор Velxio с схемой светофора на Arduino Uno"
+    }
   }
 }

frontend/src/i18n/locales/zh-cn/common.json

@@ -24,5 +24,16 @@
   },
   "footer": {
     "about": "Velxio 是一款免费的开源电路和微控制器模拟器，完全在您的浏览器中运行。支持 Arduino、ESP32、RP2040 和 ATtiny85，配备 SPICE 精度的模拟协同仿真。专为通过实践学习的创客、学生和嵌入式工程师打造。AGPLv3。"
+  },
+  "landing": {
+    "hero": {
+      "titleLine1": "Arduino、ESP32 和 Raspberry Pi。",
+      "titleAccent": "就在您的浏览器中。",
+      "subtitle": "编写代码、连接元件、点击运行。19 款开发板，48+ 元件，真实 CPU 模拟 —— 无需硬件、无需安装、无需云端。",
+      "ctaPrimary": "免费试用模拟器 →",
+      "ctaGithub": "在 GitHub 上查看",
+      "trustLine": "无需注册 · 100% 在浏览器中运行 · 免费且开源",
+      "imageAlt": "Velxio 编辑器中的 Arduino Uno 红绿灯电路"
+    }
   }
 }

frontend/src/pages/LandingPage.tsx

@@ -12,6 +12,7 @@ import { useTranslation } from 'react-i18next';
 import { useAuthStore } from '../store/useAuthStore';
 import { trackVisitGitHub, trackClickCTA } from '../utils/analytics';
 import { AppHeader } from '../components/layout/AppHeader';
+import { useLocalizedHref } from '../i18n/useLocalizedNavigate';
 import { useSEO } from '../utils/useSEO';
 import { getSeoMeta } from '../seoRoutes';
 import raspberryPi3Svg from '../assets/Raspberry_Pi_3_illustration.svg';
@@ -746,6 +747,7 @@ const UserMenu: React.FC = () => {
 /* ── Component ────────────────────────────────────────── */
 export const LandingPage: React.FC = () => {
   const { t } = useTranslation();
+  const localize = useLocalizedHref();
   useSEO({
     ...getSeoMeta('/')!,
     jsonLd: {
@@ -812,23 +814,19 @@ export const LandingPage: React.FC = () => {
       <section className="landing-hero">
         <div className="hero-left">
           <h1 className="hero-title">
-            Arduino, ESP32 &amp; Raspberry Pi.
+            {t('landing.hero.titleLine1')}
             <br />
-            <span className="hero-accent">Right in your browser.</span>
+            <span className="hero-accent">{t('landing.hero.titleAccent')}</span>
           </h1>
-          <p className="hero-subtitle">
-            Write code, wire up components, hit run.
-            19 boards, 48+ parts, real CPU emulation —
-            no hardware, no installation, no cloud.
-          </p>
+          <p className="hero-subtitle">{t('landing.hero.subtitle')}</p>
           <div className="hero-ctas">
             <Link
-              to="/editor"
+              to={localize('/editor')}
               className="cta-primary"
               onClick={() => trackClickCTA('landing', '/editor')}
             >
               <IcoZap />
-              Try Simulator Free →
+              {t('landing.hero.ctaPrimary')}
             </Link>
             <a
               href={GITHUB_URL}
@@ -838,12 +836,10 @@ export const LandingPage: React.FC = () => {
               className="cta-secondary"
             >
               <IcoGitHub />
-              View on GitHub
+              {t('landing.hero.ctaGithub')}
             </a>
           </div>
-          <p className="hero-trust-line">
-            No signup required · Runs 100% in your browser · Free &amp; open-source
-          </p>
+          <p className="hero-trust-line">{t('landing.hero.trustLine')}</p>
         </div>
         <div className="hero-right">
           <picture>
@@ -851,7 +847,7 @@ export const LandingPage: React.FC = () => {
             <source srcSet="/marketing/hero-editor.png" type="image/png" />
             <img
               src="/marketing/hero-editor.png"
-              alt="Velxio editor with Arduino Uno traffic-light circuit"
+              alt={t('landing.hero.imageAlt')}
               className="hero-preview-img"
               loading="eager"
               fetchPriority="high"
@@ -1258,10 +1254,10 @@ export const LandingPage: React.FC = () => {
           <a href={GITHUB_URL} target="_blank" rel="noopener noreferrer" onClick={trackVisitGitHub}>
             GitHub
           </a>
-          <Link to="/docs">Docs</Link>
-          <Link to="/examples">Examples</Link>
-          <Link to="/editor">Editor</Link>
-          <Link to="/about">About</Link>
+          <Link to={localize('/docs')}>Docs</Link>
+          <Link to={localize('/examples')}>Examples</Link>
+          <Link to={localize('/editor')}>Editor</Link>
+          <Link to={localize('/about')}>About</Link>
         </div>
         <p className="footer-copy">{t('footer.about')}</p>
       </footer>