feat: default to the new mobile layout

Make the new mobile layout the default when no preference is stored, and
relabel the legacy 'default' option as Old (localized as Previous/older where
it reads better) while keeping its stored value for backwards compatibility.

packages/ui/src/lib/i18n/messages/en.settings.ts

@@ -1536,7 +1536,7 @@ export const settingsDict = {
   'settings.voice.page.preview.customServerLine': 'Hello! This is a preview of the custom TTS server.',
   'settings.openchamber.visual.section.colorMode': 'Color Mode',
   'settings.openchamber.visual.section.mobileLayout': 'Mobile Layout',
-  'settings.openchamber.visual.option.mobileLayout.default': 'Default',
+  'settings.openchamber.visual.option.mobileLayout.default': 'Old',
   'settings.openchamber.visual.option.mobileLayout.new': 'New',
   'settings.openchamber.visual.section.localization': 'Localization',
   'settings.openchamber.visual.section.spacingAndLayout': 'Spacing & Layout',

packages/ui/src/lib/i18n/messages/es.settings.ts

@@ -1503,7 +1503,7 @@ export const settingsDict = {
   "settings.voice.page.preview.customServerLine": "¡Hola! Esta es una previsualización del servidor TTS personalizado.",
   "settings.openchamber.visual.section.colorMode": "Modo de color",
   "settings.openchamber.visual.section.mobileLayout": "Diseño móvil",
-  "settings.openchamber.visual.option.mobileLayout.default": "Predeterminado",
+  "settings.openchamber.visual.option.mobileLayout.default": "Anterior",
   "settings.openchamber.visual.option.mobileLayout.new": "Nuevo",
   "settings.openchamber.visual.section.localization": "Localización",
   "settings.openchamber.visual.section.spacingAndLayout": "Espaciado y diseño",

packages/ui/src/lib/i18n/messages/ko.settings.ts

@@ -1503,7 +1503,7 @@ export const settingsDict = {
   'settings.voice.page.preview.customServerLine': '안녕하세요! 사용자 정의 TTS 서버 미리보기입니다.',
   'settings.openchamber.visual.section.colorMode': '색상 모드',
   'settings.openchamber.visual.section.mobileLayout': '모바일 레이아웃',
-  'settings.openchamber.visual.option.mobileLayout.default': '기본값',
+  'settings.openchamber.visual.option.mobileLayout.default': '이전',
   'settings.openchamber.visual.option.mobileLayout.new': '새로움',
   'settings.openchamber.visual.section.localization': '지역화',
   'settings.openchamber.visual.section.spacingAndLayout': '간격 및 레이아웃',

packages/ui/src/lib/i18n/messages/pl.settings.ts

@@ -1008,7 +1008,7 @@ export const settingsDict = {
   'settings.openchamber.visual.section.chatRenderModeAria': 'Tryb renderowania czatu',
   'settings.openchamber.visual.section.colorMode': 'Tryb kolorów',
   'settings.openchamber.visual.section.mobileLayout': 'Układ mobilny',
-  'settings.openchamber.visual.option.mobileLayout.default': 'Domyślny',
+  'settings.openchamber.visual.option.mobileLayout.default': 'Poprzedni',
   'settings.openchamber.visual.option.mobileLayout.new': 'Nowy',
   'settings.openchamber.visual.section.diffLayout': 'Układ diffa',
   'settings.openchamber.visual.section.diffLayoutAria': 'Układ diffa',

packages/ui/src/lib/i18n/messages/pt-BR.settings.ts

@@ -1503,7 +1503,7 @@ export const settingsDict = {
   "settings.voice.page.preview.customServerLine": "Olá! Esta é uma prévia do servidor TTS personalizado.",
   "settings.openchamber.visual.section.colorMode": "Modo de cor",
   "settings.openchamber.visual.section.mobileLayout": "Layout móvel",
-  "settings.openchamber.visual.option.mobileLayout.default": "Padrão",
+  "settings.openchamber.visual.option.mobileLayout.default": "Anterior",
   "settings.openchamber.visual.option.mobileLayout.new": "Novo",
   "settings.openchamber.visual.section.localization": "Localização",
   "settings.openchamber.visual.section.spacingAndLayout": "Espaçamento e layout",

packages/ui/src/lib/i18n/messages/uk.settings.ts

@@ -1503,7 +1503,7 @@ export const settingsDict = {
   "settings.voice.page.preview.customServerLine": "Привіт! Це попередній перегляд спеціального сервера TTS.",
   "settings.openchamber.visual.section.colorMode": "Режим теми",
   "settings.openchamber.visual.section.mobileLayout": "Мобільний макет",
-  "settings.openchamber.visual.option.mobileLayout.default": "Стандартний",
+  "settings.openchamber.visual.option.mobileLayout.default": "Попередній",
   "settings.openchamber.visual.option.mobileLayout.new": "Новий",
   "settings.openchamber.visual.section.localization": "Локалізація",
   "settings.openchamber.visual.section.spacingAndLayout": "Відступи й компонування",

packages/ui/src/lib/i18n/messages/zh-CN.settings.ts

@@ -1503,7 +1503,7 @@ export const settingsDict = {
   'settings.voice.page.preview.customServerLine': '你好！这是自定义 TTS 服务器的预览。',
   'settings.openchamber.visual.section.colorMode': '颜色模式',
   'settings.openchamber.visual.section.mobileLayout': '移动端布局',
-  'settings.openchamber.visual.option.mobileLayout.default': '默认',
+  'settings.openchamber.visual.option.mobileLayout.default': '旧版',
   'settings.openchamber.visual.option.mobileLayout.new': '新版',
   'settings.openchamber.visual.section.localization': '本地化',
   'settings.openchamber.visual.section.spacingAndLayout': '间距与布局',

packages/ui/src/lib/i18n/messages/zh-TW.settings.ts

@@ -1469,7 +1469,7 @@
   'settings.openchamber.visual.field.mobileKeyboardModeAria': '行動裝置鍵盤行為',
   'settings.openchamber.visual.field.selectMobileKeyboardModePlaceholder': '選擇鍵盤行為',
   'settings.openchamber.visual.actions.resetMobileKeyboardModeAria': '重設行動裝置鍵盤行為',
-  'settings.openchamber.visual.option.mobileLayout.default': '預設',
+  'settings.openchamber.visual.option.mobileLayout.default': '舊版',
   'settings.openchamber.visual.option.mobileLayout.new': '新版',
   'settings.openchamber.visual.field.interfaceFontSize': '介面字體大小',
   'settings.openchamber.visual.field.interfaceFont': '介面字體',

packages/ui/src/lib/mobileLayoutPreference.ts

@@ -3,18 +3,20 @@ export type MobileLayoutPreference = 'default' | 'new';
 const MOBILE_LAYOUT_PREFERENCE_KEY = 'openchamber-mobile-layout';
 
 export const normalizeMobileLayoutPreference = (value: unknown): MobileLayoutPreference => {
-  return value === 'new' ? 'new' : 'default';
+  // 'new' is the default; only an explicit 'default' (the legacy/"Old" layout)
+  // opts out of it.
+  return value === 'default' ? 'default' : 'new';
 };
 
 export const getStoredMobileLayoutPreference = (): MobileLayoutPreference => {
   if (typeof window === 'undefined') {
-    return 'default';
+    return 'new';
   }
 
   try {
     return normalizeMobileLayoutPreference(window.localStorage.getItem(MOBILE_LAYOUT_PREFERENCE_KEY));
   } catch {
-    return 'default';
+    return 'new';
   }
 };