Built-in TypeScript language features fail to activate: placed in web worker host, dist/browser bundle missing (404) #8039

Summary

In code-server 4.140.0 (Code 1.140.0) — and also 4.139.1 — the built-in vscode.typescript-language-features extension never activates in the browser client, so TypeScript/JavaScript diagnostics and IntelliSense are missing in the editor. The extension declares a browser entry (./dist/browser/extension), but the shipped release tarball has no lib/vscode/extensions/typescript-language-features/dist/browser/ directory. The web client places the extension in the web worker extension host, the bundle request returns 404, and the extension stays in "Activating…".

Steps to reproduce

1. Download and extract code-server-4.140.0-linux-amd64.tar.gz from the GitHub release.
2. Start it: code-server --auth none --host 127.0.0.1 --port 8443 <folder>.
3. In the folder, create a tsconfig.json ({"compilerOptions":{"strict":true}}) and probe.ts containing const n: number = "x".
4. Open probe.ts in a Chromium-based browser and wait.

Expected

A TS2322 diagnostic ("Type 'string' is not assignable to type 'number'") appears in the editor and in the Problems panel, as it does in OpenVSCode Server 1.109.5 with the same steps.

Actual

• Problems: "No problems have been detected in the workspace."
• Developer: Show Running Extensions lists "JavaScript and TypeScript Language Features — web worker — Activating…". All other built-in extensions run in the remote host.
• The browser console shows Extension 'vscode.typescript-language-features' is already registered (repeated) and Activating extension 'vscode.typescript-language-features' failed: Not Found.
• Network: GET /stable-<commit>/vscode-remote-resource?path=…/lib/vscode/extensions/typescript-language-features/dist/browser/extension… → 404.
• ls lib/vscode/extensions/typescript-language-features/dist → extension.js only.

Reproduced in headless Chromium 153 (Playwright) and in headed Google Chrome 151, with fresh user-data/extensions directories.

Things that did not help

• User setting "remote.extensionKind": {"vscode.typescript-language-features": ["workspace"]} (confirmed loaded via Open User Settings (JSON))
• User setting "extensions.webWorker": false
• Removing the built-in copilot extension directory
• Adding "extensionKind": {"vscode.typescript-language-features": ["workspace"]} to lib/vscode/product.json

Environment

• code-server 4.140.0 (Code 1.140.0, commit ccc19ad) and 4.139.1, linux-amd64 release tarballs
• Linux x86_64, Node bundled with the release
• Browsers: Chromium 153.0.8010.12, Google Chrome 151.0.7922.137