Use LazyBarrel to improve IDE performance

まだ誰も着手していません。

### 🔍 Search Terms

"re-export", "barrel file", "optimization", "performance"

### ✅ Viability Checklist

- [x] This wouldn't be a breaking change in existing TypeScript/JavaScript code
- [x] This wouldn't change the runtime behavior of existing JavaScript code
- [x] This could be implemented without emitting different JS based on the types of the expressions
- [x] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
- [x] This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
- [x] This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

### ⭐ Suggestion

Can the Typescript Language Server implement and use its own version of the [LazyBarrel](https://rspack.rs/guide/optimization/lazy-barrel) optimization as an experimental feature to improve IDE performance?

### 📃 Motivating Example

This feature should improve IDE performance (e.g. type highlight) and reduce the impact of barrel files on Typescript codebases.

Explanation provided on [LazyBarrel](https://rspack.rs/guide/optimization/lazy-barrel).

### 💻 Use Cases

1. What do you want to use this for?

Improving IDE performance.

2. What shortcomings exist with current approaches?

Barrel files have a significant impact on IDE performance in Typescript codebases.

3. What workarounds are you using in the meantime?

Manually de-barreling packages.

TypeScript Language Server とリンク先の LazyBarrel の説明から始めて、提案されている最適化とその範囲を理解してください。実験的な統合ポイントと、IDE パフォーマンスを測定できるシナリオを特定してください。実装完了時には、ランタイムの動作を変更せずに、barrel を多用する TypeScript コードのパフォーマンスが向上したことを示せるようにしてください。

索引モデルが issue の本文から書いたものです。