Restore lint corrections from #7989 (#7997)

* Ignore braces when building Sandpack file map

Previously, `createFileMap` split the MDX meta string on spaces and assumed the first token was the filename. Once we prefixed code fences with `{expectedErrors: ...}`, it would incorrectly parse the meta and crash.

This PR updates createFileMap to skip tokens in the meta containing a start and end brace pair (using a stack to ensure we close on the correct brace) while tokenizing the meta string as expected.

Test plan: pages reported in #7994 no longer crash on the next PR

Closes #7994

* Restore lint corrections from #7989

Reverts the revert now that we've fixed the bug. These pages should no longer crash:

https://react-dev-git-pr7997-fbopensource.vercel.app/learn/referencing-values-with-refs
https://react-dev-git-pr7997-fbopensource.vercel.app/learn/synchronizing-with-effects
https://react-dev-git-pr7997-fbopensource.vercel.app/learn/separating-events-from-effects
https://react-dev-git-pr7997-fbopensource.vercel.app/learn/removing-effect-dependencies
https://react-dev-git-pr7997-fbopensource.vercel.app/learn/you-might-not-need-an-effect

Author: poteto

src/content/learn/describing-the-ui.md

@@ -474,7 +474,7 @@ By strictly only writing your components as pure functions, you can avoid an ent
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [5]}}
 let guest = 0;
 
 function Cup() {

src/content/learn/escape-hatches.md

@@ -201,7 +201,7 @@ There are two common cases in which you don't need Effects:
 
 For example, you don't need an Effect to adjust some state based on other state:
 
-```js {5-9}
+```js {expectedErrors: {'react-compiler': [8]}} {5-9}
 function Form() {
   const [firstName, setFirstName] = useState('Taylor');
   const [lastName, setLastName] = useState('Swift');

src/content/learn/keeping-components-pure.md

@@ -93,7 +93,7 @@ Here is a component that breaks this rule:
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [5]}}
 let guest = 0;
 
 function Cup() {
@@ -380,7 +380,7 @@ The buggy code is in `Profile.js`. Make sure you read it all from top to bottom!
 
 <Sandpack>
 
-```js src/Profile.js
+```js {expectedErrors: {'react-compiler': [7]}} src/Profile.js
 import Panel from './Panel.js';
 import { getImageUrl } from './utils.js';
 
@@ -602,7 +602,7 @@ export default function StoryTray({ stories }) {
 }
 ```
 
-```js src/App.js hidden
+```js {expectedErrors: {'react-compiler': [16]}} src/App.js hidden
 import { useState, useEffect } from 'react';
 import StoryTray from './StoryTray.js';
 
@@ -698,7 +698,7 @@ export default function StoryTray({ stories }) {
 }
 ```
 
-```js src/App.js hidden
+```js {expectedErrors: {'react-compiler': [16]}} src/App.js hidden
 import { useState, useEffect } from 'react';
 import StoryTray from './StoryTray.js';
 
@@ -790,7 +790,7 @@ export default function StoryTray({ stories }) {
 }
 ```
 
-```js src/App.js hidden
+```js {expectedErrors: {'react-compiler': [16]}} src/App.js hidden
 import { useState, useEffect } from 'react';
 import StoryTray from './StoryTray.js';
 

src/content/learn/lifecycle-of-reactive-effects.md

@@ -1131,7 +1131,7 @@ If you see a linter rule being suppressed, remove the suppression! That's where
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [16]}}
 import { useState, useEffect } from 'react';
 
 export default function App() {
@@ -1374,7 +1374,7 @@ export default function App() {
 }
 ```
 
-```js src/ChatRoom.js active
+```js {expectedErrors: {'react-compiler': [8]}} src/ChatRoom.js active
 import { useState, useEffect } from 'react';
 
 export default function ChatRoom({ roomId, createConnection }) {

src/content/learn/preserving-and-resetting-state.md

@@ -704,7 +704,7 @@ Here, the `MyTextField` component function is defined *inside* `MyComponent`:
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [7]}}
 import { useState } from 'react';
 
 export default function MyComponent() {

src/content/learn/react-compiler/introduction.md

@@ -28,7 +28,7 @@ React Compiler automatically optimizes your React application at build time. Rea
 
 Without the compiler, you need to manually memoize components and values to optimize re-renders:
 
-```js
+```js {expectedErrors: {'react-compiler': [4]}}
 import { useMemo, useCallback, memo } from 'react';
 
 const ExpensiveComponent = memo(function ExpensiveComponent({ data, onClick }) {

src/content/learn/referencing-values-with-refs.md

@@ -211,7 +211,7 @@ If you tried to implement this with a ref, React would never re-render the compo
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [13]}}
 import { useRef } from 'react';
 
 export default function Counter() {
@@ -313,7 +313,7 @@ Regular variables like `let timeoutID` don't "survive" between re-renders becaus
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [10]}}
 import { useState } from 'react';
 
 export default function Chat() {
@@ -418,7 +418,7 @@ This button is supposed to toggle between showing "On" and "Off". However, it al
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [10]}}
 import { useRef } from 'react';
 
 export default function Toggle() {

src/content/learn/removing-effect-dependencies.md

@@ -303,7 +303,7 @@ Suppressing the linter leads to very unintuitive bugs that are hard to find and
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [14]}}
 import { useState, useEffect } from 'react';
 
 export default function Timer() {
@@ -794,7 +794,7 @@ It is important to declare it as a dependency! This ensures, for example, that i
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [10]}}
 import { useState, useEffect } from 'react';
 import { createConnection } from './chat.js';
 

src/content/learn/responding-to-events.md

@@ -546,7 +546,7 @@ Clicking this button is supposed to switch the page background between white and
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [5, 7]}}
 export default function LightSwitch() {
   function handleClick() {
     let bodyStyle = document.body.style;

src/content/learn/separating-events-from-effects.md

@@ -711,7 +711,7 @@ Here, `url` inside `onVisit` corresponds to the *latest* `url` (which could have
 
 In the existing codebases, you may sometimes see the lint rule suppressed like this:
 
-```js {7-9}
+```js {expectedErrors: {'react-compiler': [8]}} {7-9}
 function Page({ url }) {
   const { items } = useContext(ShoppingCartContext);
   const numberOfItems = items.length;
@@ -735,7 +735,7 @@ Can you see why?
 
 <Sandpack>
 
-```js
+```js {expectedErrors: {'react-compiler': [16]}}
 import { useState, useEffect } from 'react';
 
 export default function App() {
@@ -990,7 +990,7 @@ To fix this code, it's enough to follow the rules.
 ```
 
 
-```js
+```js {expectedErrors: {'react-compiler': [14]}}
 import { useState, useEffect } from 'react';
 
 export default function Timer() {