eclipse-theia/theia

Follow up of #17673 . With Theia dropping support for React 18, we should check where we can improve existing code by using new React 19 features or APIs.

Bug Description: On Linux, @parcel/watcher's inotify backend needs one watch per directory. The initial subscribe() walks the tree recursively, but a directory that appears later only gets a watch on itself (InotifyBackend::handleSubscription → watchDir, no scan of its contents). Anything already inside it at that moment never gets a watch for the rest of the backend's life — and that is the normal case for mkdir -p, git checkout, unzip/import or a tree renamed into the workspace, because the next level is created microseconds after its parent. Edits under such a subtree never reach editors, the navigator or language servers (didChangeWatchedFiles) until the backend restarts. No error, no log line. Upstream: parcel-bundler/watcher#97 (open since 2022, from microsoft/vscode#142694 — VS Code closed it as upstream and has no workaround; a window reload heals it) and parcel-bundler/watcher#243. It was noted when Theia moved from nsfw to parcel (#12784) but never tracked here. Measure

Feature Description: Support native VS Code UX for the walkthroughs. This is a follow-up of #17309 For example, but not limited to: the walkthrough step content is inside the step card, not next to it right next to the step, there is optional media (SVG, PNG) to render responsive UI: when there is no horizontal space, do not render the media support inline codeblocks support markdown with referenced media VS Code native Mark Done button VS Code native colors for completed steps Actual: Expected: Screen.Recording.2026-08-25.at.10.43.52.mov

In @theia/bundle-plugin (observed in 1.73.1), the esbuild plugin replaces @vscode/ripgrep with a shim: export const rgPath = require("path").join(__dirname, './native/rg...'), copying the binary next to the bundle. In an electron-builder packaged app, the bundle typically lives inside app.asar. Electron redirects require() of .node files to app.asar.unpacked, but does not redirect child_process.spawn. The shim drops the asar → asar.unpacked handling that @vscode/ripgrep itself performs, so rgPath points inside the archive and every spawn fails — ENOENT on Windows, ENOTDIR on macOS — and file search silently returns 0 results. The .node files in the same directory keep working (require is redirected), which makes this asymmetry hard to diagnose. Suggested fix: emit the replacement in the shim, e.g. .replace(/\bapp\.asar([\\/])/, "app.asar.unpacked$1"), and/or document that packagers must add the copied native directory to asarUnpack. Downstream report with full diagnosis and measu

Allow users to re-dock detached secondary windows into the main application window Problem Statement Currently, when a secondary window is detached from the main application, there is no dedicated way to dock it back. The only available option is to close the detached window using the X button. This behavior is unintuitive because users generally expect the X button to close the window completely rather than return it to the main application. As a result, users may hesitate to close the window or be unsure how to restore the original layout. User Need As a user, I want to re-dock a detached secondary window into the main application window without closing it, so that I can easily restore my preferred workspace. Proposed Solutions One or both of the following interaction patterns should be supported: Option 1: Re-dock Button Provide a dedicated "Dock" or "Return to Main Window" button in the title bar or toolbar of the detached window. Clicking the button docks the window back into its