feat(tanstackstart-react): update docs after devinxi (#14036)

## Upgrade TanStack Start React Docs after Vinxi has been removed

Apply the necessary upgrades as described in the [TSS
migration](TanStack/router#2863 (comment)).

Regards:
- getsentry/sentry-javascript#14990
- getsentry/sentry-javascript#16540

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- [x] None: Not urgent, can wait up to 1 week+

## SLA

- Teamwork makes the dream work, so please add a reviewer to your PRs.
- Please give the docs team up to 1 week to review your PR unless you've
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Thanks in advance for your help!

## PRE-MERGE CHECKLIST

*Make sure you've checked the following before merging your changes:*

- [ ] Checked Vercel preview for correctness, including links
- [ ] PR was reviewed and approved by any necessary SMEs (subject matter
experts)
- [ ] PR was reviewed and approved by a member of the [Sentry docs
team](https://github.com/orgs/getsentry/teams/docs)

## LEGAL BOILERPLATE

<!-- Sentry employees and contractors can delete or ignore this section.
-->

Look, I get it. The entity doing business as "Sentry" was incorporated
in the State of Delaware in 2015 as Functional Software, Inc. and is
gonna need some rights from me in order to utilize my contributions in
this here PR. So here's the deal: I retain all rights, title and
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contributions, under Sentry's choice of terms.

## EXTRA RESOURCES

- [Sentry Docs contributor guide](https://docs.sentry.io/contributing/)

Author: KiwiKilian

docs/platforms/javascript/guides/tanstackstart-react/index.mdx

@@ -31,44 +31,9 @@ pnpm add @sentry/tanstackstart-react
 
 ## Step 2: Configure
 
-Extend your app's default TanStack Start configuration by adding `wrapVinxiConfigWithSentry` to your `app.config.ts` file:
+Add the following initialization code to your `src/client.tsx` file to initialize Sentry on the client:
 
-```TypeScript {filename:app.config.ts}
-import { defineConfig } from "@tanstack/react-start/config";
-import { wrapVinxiConfigWithSentry } from "@sentry/tanstackstart-react";
-
-const config = defineConfig({
-    // ... your other TanStack Start config
-})
-
-export default wrapVinxiConfigWithSentry(config, {
-  org: "___ORG_SLUG___",
-  project: "___PROJECT_SLUG___",
-  authToken: process.env.SENTRY_AUTH_TOKEN,
-
-  // Only print logs for uploading source maps in CI
-  // Set to `true` to suppress logs
-  silent: !process.env.CI,
-});
-```
-
-{/* TODO(lforst): Remove "in future versions of this SDK," */}
-
-In future versions of this SDK, setting the `SENTRY_AUTH_TOKEN` environment variable will upload sourcemaps for you to see unminified errors in Sentry:
-
-```sh {filename:.env}
-SENTRY_AUTH_TOKEN=___ORG_AUTH_TOKEN___
-```
-
-<Alert level="warning" title="Important">
-
-Make sure to keep your auth token secret and out of version control.
-
-</Alert>
-
-Add the following initialization code to your `app/client.tsx` file to initialize Sentry on the client:
-
-```tsx {filename:app/client.tsx}
+```tsx {filename:src/client.tsx}
 import { hydrateRoot } from "react-dom/client";
 import { StartClient } from "@tanstack/react-start";
 import { createRouter } from "./router";
@@ -124,9 +89,9 @@ Sentry.init({
 hydrateRoot(document, <StartClient router={router} />);
 ```
 
-Add the following initialization code anywhere in your `app/ssr.tsx` file to initialize Sentry on the server:
+Add the following initialization code anywhere in your `src/server.tsx` file to initialize Sentry on the server:
 
-```tsx {filename:app/ssr.tsx}
+```tsx {filename:src/server.tsx}
 import * as Sentry from "@sentry/tanstackstart-react";
 
 Sentry.init({
@@ -154,7 +119,7 @@ Sentry.init({
 
 Wrap TanStack Start's `createRootRoute` function using `wrapCreateRootRouteWithSentry` to apply tracing to Server-Side Rendering (SSR):
 
-```tsx {filename:app/routes/__root.tsx} {3,6}
+```tsx {filename:src/routes/__root.tsx} {3,6}
 import type { ReactNode } from "react";
 import { createRootRoute } from "@tanstack/react-router";
 import { wrapCreateRootRouteWithSentry } from "@sentry/tanstackstart-router";
@@ -167,7 +132,7 @@ export const Route = wrapCreateRootRouteWithSentry(createRootRoute)({
 
 Wrap TanStack Start's `defaultStreamHandler` function using `wrapStreamHandlerWithSentry` to instrument requests to your server:
 
-```tsx {filename:app/ssr.tsx} {12}
+```tsx {filename:src/server.tsx} {12}
 import {
   createStartHandler,
   defaultStreamHandler,
@@ -186,11 +151,11 @@ Add the `sentryGlobalServerMiddlewareHandler` to your global middlewares to inst
 
 <Alert level="info">
 
-If you haven't done so, create a `app/global-middleware.ts` file as outlined in the [TanStack Start Docs for Global Middleware](https://tanstack.com/start/latest/docs/framework/react/middleware#global-middleware).
+If you haven't done so, create a `src/global-middleware.ts` file as outlined in the [TanStack Start Docs for Global Middleware](https://tanstack.com/start/latest/docs/framework/react/middleware#global-middleware).
 
 </Alert>
 
-```ts {filename:app/global-middleware.ts}
+```ts {filename:src/global-middleware.ts}
 import {
   createMiddleware,
   registerGlobalMiddleware,
@@ -199,7 +164,7 @@ import * as Sentry from "@sentry/tanstackstart-react";
 
 registerGlobalMiddleware({
   middleware: [
-    createMiddleware().server(Sentry.sentryGlobalServerMiddlewareHandler()),
+    createMiddleware({ type: 'function' }).server(Sentry.sentryGlobalServerMiddlewareHandler()),
   ],
 });
 ```
@@ -272,7 +237,7 @@ To verify that Sentry captures errors and creates issues in your Sentry project,
 
 To test tracing, create a test API route like `/api/sentry-example-api`:
 
-```typescript {filename:app/routes/api/sentry-example-api.ts}
+```typescript {filename:src/routes/api/sentry-example-api.ts}
 import { json } from "@tanstack/react-start";
 import { createAPIFileRoute } from "@tanstack/react-start/api";