feat(welcome): rename "Speed" control to "Video speed" (4-lang)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

simulator/static/i18n.js

@@ -31,7 +31,7 @@
     "knobs.feel":     { en: "Feel", es: "Sentir", fr: "Ressentir", ja: "感じる" },
     "knobs.mood":     { en: "Mood — dark ◀ 0 ▶ light", es: "Ánimo — oscuro ◀ 0 ▶ claro", fr: "Humeur — sombre ◀ 0 ▶ clair", ja: "ムード — 暗 ◀ 0 ▶ 明" },
     "devmode.label":  { en: "Dev Mode", es: "Modo desarrollo", fr: "Mode dév", ja: "開発モード" },
-    "speed.label":    { en: "Speed", es: "Velocidad", fr: "Vitesse", ja: "再生速度" },
+    "speed.label":    { en: "Video speed", es: "Velocidad de vídeo", fr: "Vitesse vidéo", ja: "映像速度" },
     "rm.label":       { en: "Reduce motion", es: "Reducir movimiento", fr: "Réduire les animations", ja: "動きを減らす" },
     "warn.title":     { en: "Heads up — motion & flashing", es: "Atención — movimiento y destellos", fr: "Attention — mouvement et flashs", ja: "ご注意 — 動きと点滅" },
     "warn.body":      { en: "This experience contains continuous motion, flashing, and shifting imagery. If you are sensitive to motion or flashing light, turn on “Reduce motion” below before you launch — altitude changes will cut instantly instead of animating.", es: "Esta experiencia contiene movimiento continuo, destellos e imágenes cambiantes. Si eres sensible al movimiento o a las luces parpadeantes, activa «Reducir movimiento» abajo antes de iniciar — los cambios de altitud serán cortes instantáneos en vez de animarse.", fr: "Cette expérience contient des mouvements continus, des flashs et des images changeantes. Si vous êtes sensible au mouvement ou aux lumières clignotantes, activez « Réduire les animations » ci-dessous avant de lancer — les changements d’altitude seront des coupes instantanées au lieu de s’animer.", ja: "この体験には連続した動き、点滅、変化する映像が含まれます。動きや点滅する光に敏感な方は、起動する前に下の「動きを減らす」をオンにしてください — 高度の変化はアニメーションせず瞬時に切り替わります。" },

simulator/static/index.html

@@ -21,7 +21,7 @@
         <label class="lang-pick">🌐
           <select id="welcome-lang" aria-label="Language"></select>
         </label>
-        <label class="audio-level play-speed"><span data-i18n="speed.label">Speed</span>
+        <label class="audio-level play-speed"><span data-i18n="speed.label">Video speed</span>
           <input type="range" id="welcome-play-speed" min="0" max="4" step="any" value="1"
                  list="play-speed-ticks" aria-describedby="welcome-play-speed-val" />
           <span id="welcome-play-speed-val">1.00×</span>
@@ -76,7 +76,7 @@
           <input type="range" id="audio" min="0" max="10" value="0" step="1" />
           <span id="audio-level-val">0</span>/10
         </label>
-        <label class="audio-level play-speed"><span data-i18n="speed.label">Speed</span>
+        <label class="audio-level play-speed"><span data-i18n="speed.label">Video speed</span>
           <input type="range" id="play-speed" min="0" max="4" step="any" value="1"
                  list="play-speed-ticks" aria-describedby="play-speed-val" />
           <span id="play-speed-val">1.00×</span>