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/components/admin/admin-breadcrumb.tsx

@@ -11,6 +11,7 @@ import {
   BreadcrumbPage,
   BreadcrumbSeparator,
 } from "@/components/ui/breadcrumb";
+import { adminNavLabel } from "@/lib/admin-nav-label";
 import { ADMIN_BASE } from "@/modules/_config/admin-nav";
 import { useAdminProfile } from "@/stores/admin-session";
 import React from "react";
@@ -21,29 +22,6 @@ const DRAW_ROUTE_LABELS: Record<string, string> = {
   results: "Results",
 };
 
-const NAV_TRANSLATION_KEYS: Record<string, string> = {
-  dashboard: "dashboard",
-  admin_users: "admin_users",
-  admin_roles: "admin_roles",
-  players: "players",
-  currencies: "currencies",
-  wallet: "wallet",
-  draws: "draws",
-  rules_plays: "rules_plays",
-  rules_odds: "rules_odds",
-  jackpot: "jackpot",
-  risk_cap: "risk_cap",
-  risk: "risk",
-  settlement: "settlement",
-  reconcile: "reconcile",
-  reports: "reports",
-  tickets: "tickets",
-  audit: "audit",
-  settings: "settings",
-  integration: "integration",
-  config: "config",
-};
-
 const RULES_ROUTE_LABELS: Record<string, string> = {
   plays: "nav.items.plays",
   odds: "nav.rulesOddsTitle",
@@ -113,13 +91,7 @@ export function AdminBreadcrumb() {
         .sort((a, b) => b.href.length - a.href.length)[0];
 
       if (navItem && navItem.href !== ADMIN_BASE) {
-        const translatedNavLabel =
-          NAV_TRANSLATION_KEYS[navItem.segment] != null
-            ? t(`nav.${NAV_TRANSLATION_KEYS[navItem.segment]}`, {
-                ns: "common",
-                defaultValue: navItem.label,
-              })
-            : navItem.label;
+        const translatedNavLabel = adminNavLabel(navItem.segment, t, navItem.label);
         breadcrumbs.push({
           label: translatedNavLabel,
           href: navItem.href,