docs(cli): add PowerShell curl examples for Windows users

[terminalchai]

What does this PR do?

The CLI reference (docs/cli.md) only shows Unix curl shell examples. On Windows, PowerShell aliases \curl\ to \Invoke-WebRequest, which silently breaks every shell example when copy-pasted.

This PR:

• Adds a tip block at the top of the CLI reference noting the \curl\ alias issue and recommending \curl.exe\ with a file-based JSON body for PowerShell.
• Adds two PowerShell-specific code blocks at the end of the doc showing how to call a local agent and a deployed agent using \curl.exe\ + \ConvertTo-Json\ + a temp file.

Checklist

• Tests added/updated
• \pnpm build\ passes
• \pnpm test\ passes
• \pnpm lint\ passes