i18n: language picker in the bottom-right corner

Replaces the EN/ES/RU buttons in the Visual Presets dock with a picker
that scales to many languages: a globe button with the current code
next to the POWER UP chip, opening a list of languages named in their
own language with their codes, the current one first and checked. A
search field appears past 8 languages. Keyboard: arrows, Home/End,
Enter/Space, Esc, type-ahead; keys stay in the list while it is open.
Choosing a language still asks before dropping unsaved work, then
reloads. Phones get the globe alone and a full-width sheet; the layout
uses logical properties for right-to-left languages.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/i18n/locales/es.json

@@ -22,7 +22,11 @@
   "Globe actions": "Acciones del globo",
   "Reset camera and return to full globe view": "Restablecer la cámara y volver a la vista del globo completo",
   "loading frames": "cargando fotogramas",
-  "Language": "Idioma",
+  "Language: {language}": "Idioma: {language}",
+  "Change the interface language": "Cambiar el idioma de la interfaz",
+  "Interface language": "Idioma de la interfaz",
+  "Search languages": "Buscar idioma",
+  "No matching languages": "No hay idiomas que coincidan",
   "Loading Google 3D Tiles...": "Cargando Google 3D Tiles...",
   "Loading the keyless globe...": "Cargando el globo sin clave...",
   "Initializing systems...": "Inicializando sistemas...",