refactor(layout, i18n, admin): 优化布局结构与多语言支持

调整 AdminShell 组件的子组件顺序，提升代码可读性。更新 admin-breadcrumb 组件，简化导航标签翻译逻辑，确保多语言支持的一致性。重构 admin-language-switcher 组件，优化语言切换的用户体验，增强界面交互性。更新多语言配置，新增登录界面的副标题，提升用户体验。

src/i18n/locales/zh/common.json

@@ -54,7 +54,8 @@
   },
   "aria": {
     "expand": "展开",
-    "collapse": "收起"
+    "collapse": "收起",
+    "rowActionsMenu": "行操作菜单"
   },
   "export": {
     "drawsList": { "filename": "期号列表", "sheetName": "期号列表" },
@@ -148,14 +149,16 @@
     "audit": "审计日志",
     "settings": "系统设置",
     "account": "账号设置",
-    "integration": "主站接入站点",
+    "integration": "接入站点",
     "config": "运营配置"
   },
   "sidebar": {
     "workspace": "工作台"
   },
   "auth": {
-    "checking": "正在校验登录状态…"
+    "checking": "正在校验登录状态…",
+    "checkingShort": "正在进入工作台…",
+    "sessionExpired": "登录已失效，请重新登录"
   },
   "confirm": {
     "cancel": "取消",