Avoid OS state changes in portable mode

[dmitrivMS]

Fixes #239139

[Copilot]

Pull request overview

This PR prevents VS Code from making OS-level state changes when running in portable mode, ensuring the application leaves no traces on the host machine.

Changes:

• Added isPortable property to IEnvironmentMainService that checks the VSCODE_PORTABLE environment variable
• Updated workspacesHistoryMainService.ts to skip OS-level recent document tracking on Windows and macOS when in portable mode
• Updated electronUrlListener.ts to skip protocol handler registration on Windows when in portable mode

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/vs/platform/environment/electron-main/environmentMainService.ts	Adds isPortable getter to expose portable mode status via environment variable check
src/vs/platform/workspaces/electron-main/workspacesHistoryMainService.ts	Guards all OS state-changing operations (recent documents, jump lists, dock updates) with portable mode checks
src/vs/platform/url/electron-main/electronUrlListener.ts	Prevents Windows protocol handler registration in portable mode to avoid OAuth flow issues