refactor: 移除 TanStack Query 上下文初始化逻辑

- 删除 TanStack Query 上下文的初始化逻辑
- 移除对 context 模块的导出，仅保留对 devtools 模块的导出。
- 移除对旧查询上下文的依赖，直接创建并注入新的 QueryClient 实例到路由上下文中，并更新 SSR 集成配置以使用新实例。

src/integrations/tanstack-query/context.tsx

@@ -1,8 +0,0 @@
-import { QueryClient } from '@tanstack/react-query'
-
-export function getContext() {
-  const queryClient = new QueryClient()
-  return {
-    queryClient,
-  }
-}

src/integrations/tanstack-query/index.ts

@@ -1,2 +1 @@
-export * from './context'
 export * from './devtools'

src/router.tsx

@@ -1,16 +1,16 @@
+import { QueryClient } from '@tanstack/react-query'
 import { createRouter } from '@tanstack/react-router'
 import { setupRouterSsrQueryIntegration } from '@tanstack/react-router-ssr-query'
-import { getContext as getQueryContext } from './integrations/tanstack-query'
 import type { RouterContext } from './routes/__root'
 import { routeTree } from './routeTree.gen'
 
 export const getRouter = () => {
-  const queryContext = getQueryContext()
+  const queryClient = new QueryClient()
 
   const router = createRouter({
     routeTree,
     context: {
-      ...queryContext,
+      queryClient,
     } satisfies RouterContext,
 
     scrollRestoration: true,
@@ -19,7 +19,7 @@ export const getRouter = () => {
 
   setupRouterSsrQueryIntegration({
     router,
-    queryClient: queryContext.queryClient,
+    queryClient,
   })
 
   return router