task-283(后台迁移收尾/发布): admin-vue 后台工程入库 + Flask 后台整体退役

- 新后台 admin-frontend-vue 整工程入库(base=/admin-vue/、History 路由、Nginx 静态托管方案与 verify-dist 校验)
- Java AdminConsoleController 改为入口重定向: /admin|/admin.html、/login|/login.html -> /admin-vue/; 删除 classpath:static 旧 admin.html/login.html 单页与 admin.js 副本
- Flask 后台整体退役: 删除 admin_api/auth/main 蓝图、web_source 页面、static 脚本与 admin 相关测试; app.py 收敛为仅注册 version_bp(/api/version、/api/version/latest, 供桌面端更新检查)
- AdminApiGuardFilterTest 豁免样例路径 /admin.html -> /admin-vue/

admin-frontend-vue/src/styles/main.css

@@ -70,10 +70,10 @@ button, input, textarea, select { font: inherit; }
 .admin-menu .el-sub-menu__title,
 .admin-menu .el-menu-item {
   height: 42px; line-height: 42px; margin: 3px 0; padding: 0 12px;
-  border-radius: 8px; color: var(--admin-sidebar-text);
+  border-radius: 8px; color: #2f4a63;
 }
 .admin-menu .el-sub-menu__title:hover,
-.admin-menu .el-menu-item:hover { color: var(--admin-primary-strong); background: rgba(79, 120, 165, 0.09); }
+.admin-menu .el-menu-item:hover { color: #1e3b57; background: rgba(47, 93, 139, 0.16); }
 .admin-menu .el-menu-item.is-active {
   color: var(--admin-primary-strong); font-weight: 600;
   background: linear-gradient(90deg, #dce9f5, #edf4fa);
@@ -81,9 +81,9 @@ button, input, textarea, select { font: inherit; }
   box-shadow: inset 3px 0 0 #5f85ad, 0 8px 18px -16px rgba(79, 120, 165, 0.55);
 }
 .admin-menu .el-menu { background: transparent; }
-.admin-menu .el-sub-menu .el-sub-menu__icon-arrow { color: var(--admin-sidebar-text); }
-.menu-group-title { font-size: 15px; font-weight: 600; letter-spacing: .4px; color: var(--admin-sidebar-text); }
-.menu-group-title:hover { color: var(--admin-primary-strong); }
+.admin-menu .el-sub-menu .el-sub-menu__icon-arrow { color: #405b73; }
+.menu-group-title { font-size: 15px; font-weight: 600; letter-spacing: .4px; color: #405b73; }
+.menu-group-title:hover { color: #2f4a63; }
 
 .skip-link { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
 .skip-link:focus {
@@ -118,6 +118,8 @@ button, input, textarea, select { font: inherit; }
 
 .admin-content { flex: 1; min-width: 0; padding: 30px 32px 56px; overflow: auto; }
 .page-stack { display: flex; flex-direction: column; gap: 18px; }
+/* 表格操作按钮工具栏：置于表格卡片顶部、右对齐（新增/删除/导入/导出等贴近表格行操作）。 */
+.table-toolbar { display: flex; align-items: center; justify-content: flex-end; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
 .page-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; }
 .page-heading h2 { margin: 0; font-size: 20px; color: var(--admin-text); }
 .page-heading p { margin: 7px 0 0; color: var(--admin-muted); font-size: 13px; }