feat(auth): 登录页改为 ymb 品牌并支持后台配置背景图

lib/l10n/app_zh.arb

@@ -1,6 +1,6 @@
 {
   "@@locale": "zh",
-  "appName": "FruitShorts",
+  "appName": "ymb",
   "demo": "演示",
   "homeHeadline": "即刻观看",
   "homeSubtitle": "免费短剧预览。",
@@ -19,7 +19,7 @@
   "searchCancel": "取消",
   "featured": "精选",
   "recommended": "推荐",
-  "fruitShortsBrand": "FruitShorts",
+  "fruitShortsBrand": "ymb",
   "comingSoon": "即将上线",
   "authLegal": "继续即代表同意《用户协议》与《隐私政策》",
   "authLegalLead": "继续即代表同意",
@@ -349,8 +349,8 @@
   "genreDramaMystery": "剧情 · 悬疑",
   "continueWatchingHeading": "继续观看",
   "preferencesHeading": "偏好设置",
-  "brandMark": "FRUITSHORTS",
-  "shareFooter": "FruitShorts",
+  "brandMark": "YMB",
+  "shareFooter": "ymb",
   "shortsTab": "短剧",
   "myListTab": "片单",
   "watchFull": "看全集",
@@ -713,7 +713,7 @@
   "offlineDownloads": "离线缓存",
   "watchPreferences": "观看偏好",
   "contactSupport": "联系客服",
-  "vipBrandName": "FruitShorts VIP",
+  "vipBrandName": "VIP",
   "vipOpenNow": "立即开通",
   "vipBenefitFree": "全剧免费看",
   "vipBenefitNoAds": "免广告打扰",
@@ -775,6 +775,7 @@
   "dataUnavailable": "—",
   "commonQuestions": "常见问题",
   "aboutUs": "关于我们",
+  "aboutBrandName": "Your mini business",
   "aboutDescription": "专注于短剧观看与沉浸式追剧体验。",
   "versionLabel": "版本 {version}",
   "@versionLabel": {