[cherry-pick] [WindowsSandboxing]: Updated env and commandline for executing commands using pwsh.exe (#318466)

[dileepyavan]

Cherry-pick of #318466 to release/1.122.

This backports the Windows MXC PowerShell command-line/environment changes and related package and test updates.

Validation:

• npm run transpile-client
• src/vs/platform/sandbox/test/common/terminalSandboxEngine.test.ts
• src/vs/workbench/contrib/terminalContrib/chatAgentTools/test/browser/terminalSandboxService.test.ts

Focused test result: 75 passed, 0 failed.

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@anthonykim1

Matched files:

• src/vs/workbench/contrib/terminalContrib/chatAgentTools/test/browser/terminalSandboxService.test.ts

[Copilot]

Pull request overview

Cherry-pick of #318466 to release/1.122. Updates Windows MXC sandboxing to launch user commands via pwsh.exe with explicit arguments, expands the injected Windows/PowerShell environment, switches containment to processcontainer, defaults Windows cwd to the first write root, resolves Windows filesystem symlinks, and bumps @microsoft/mxc-sdk to 0.2.1. Tests are updated to cover the new command line, env vars, cwd fallback, and symlink resolution.

Changes:

• MXC config now wraps the command with "<shell>" -NoProfile -ExecutionPolicy Bypass -Command "<cmd>", uses containment: 'processcontainer', sets ui.allowWindows: true, and adds the shell's directory to readonly paths.
• SandboxHelperService.getWindowsMxcEnvironment now exports SystemRoot, PATH, ComSpec, PATHEXT, PSModulePath, USERPROFILE, APPDATA, LOCALAPPDATA, PSHOME; Windows paths are resolved through realpath via a new _toWindowsFileSystemResource converter.
• Bumped @microsoft/mxc-sdk from 0.2.0 to 0.2.1 in both root and remote manifests/lockfiles.

Show a summary per file

File	Description
src/vs/platform/sandbox/common/terminalSandboxMxcRuntime.ts	Build PowerShell-wrapped command line, switch containment to processcontainer, add shell dir to readonly, set allowWindows.
src/vs/platform/sandbox/common/terminalSandboxEngine.ts	Pass shell to MXC config, default Windows cwd to first write root, resolve Windows paths via new URI converter.
src/vs/platform/sandbox/node/sandboxHelper.ts	Inject expanded Windows/PowerShell env vars into MXC environment.
src/vs/platform/sandbox/test/common/terminalSandboxEngine.test.ts	Update Windows fixtures/assertions; add symlink-resolution test.
src/vs/workbench/contrib/terminalContrib/chatAgentTools/test/browser/terminalSandboxService.test.ts	Update remote Windows test for new env, command-line wrapping, and shell dir read access.
package.json, package-lock.json, remote/package.json, remote/package-lock.json	Bump @microsoft/mxc-sdk to 0.2.1.

Copilot's findings

Files not reviewed (1)

• remote/package-lock.json: Language not supported

• Files reviewed: 7/9 changed files
• Comments generated: 0