perf: 并行化 admin 聚合路由并完善前端缓存预取

- gateway: usage detail / provider summary / pool overview / users list 改为 tokio join 并行拉取依赖数据
- usage: interval timeline 支持自动刷新并按查询区间动态展示，取消服务端 120 分钟过滤并在 ScatterChart 统一封顶
- frontend: 新增管理端导航预取工具及 SidebarNav/MainLayout 触发，admin 读接口统一走 cachedRequest 的短期缓存
- dashboard: request detail 支持短 TTL 缓存并在 UsageRecordsTable mousedown 时预取
- data: migrate 测试在 wait_for_postgres 失败时清理子进程，避免遗留

frontend/src/layouts/MainLayout.vue

@@ -53,6 +53,7 @@
         <SidebarNav
           :items="navigation"
           :is-active="isNavActive"
+          @prefetch="prefetchNavigationItem"
         />
       </div>
 
@@ -195,6 +196,9 @@
                       :class="isNavActive(item.href)
                         ? 'bg-[#cc785c]/10 dark:bg-[#cc785c]/20 text-[#cc785c] dark:text-[#d4a27f]'
                         : 'text-[#666663] dark:text-muted-foreground hover:bg-black/5 dark:hover:bg-white/5 hover:text-[#191919] dark:hover:text-white'"
+                      @mouseenter="prefetchNavigationItem(item.href)"
+                      @focus="prefetchNavigationItem(item.href)"
+                      @pointerdown="prefetchNavigationItem(item.href)"
                       @click="mobileMenuOpen = false"
                     >
                       <component
@@ -382,6 +386,7 @@ import {
 
 import GithubIcon from '@/components/icons/GithubIcon.vue'
 import { BUILTIN_TOOL_BREADCRUMBS } from '@/config/builtin-tools'
+import { prefetchAdminNavigationTarget } from '@/utils/adminNavigationPrefetch'
 
 const router = useRouter()
 const route = useRoute()
@@ -508,6 +513,10 @@ function isNavActive(href: string) {
   return route.path === href || route.path.startsWith(`${href}/`)
 }
 
+function prefetchNavigationItem(href: string) {
+  prefetchAdminNavigationTarget(href)
+}
+
 // Navigation Data
 const navigation = computed(() => {
   const baseNavigation = [