PowerShell tool can now run commands on an attached remote machine

What

• A new session-channel version of the PowerShell tool wraps the real PowerShell tool, removes the run_in_background option from its schema, and adds a field for selecting which machine to run on. This version is only advertised when the session is serving tools to an attached machine and that condition is met (e.servedTools.has(It) && !av()); if invoked directly it throws an error explaining that PowerShell only runs on the attached machine.
• The underlying PowerShell tool definition gains a remoteExecution capability flag and a suppressesAllPermissionUpdates method.
• Its input validation now also blocks bare sleep/wait-style commands specifically when the remote call's constraints don't forbid running in the background, in addition to its previous checks.

Why

This lets Claude Code run PowerShell commands on a separate, attached Windows machine rather than only locally, while still guarding against commands (like bare sleeps) that could stall a remote session.