On Windows the official cursor-agent installer ships cursor-agent.cmd whose
body is `powershell ... -File cursor-agent.ps1 %*`. CreateProcess for a .cmd
file goes through cmd.exe, and `%*` in a batch file is expanded by
re-tokenising the original command line, which mangles arguments containing
newlines or other whitespace - most notably a long, multi-line `-p <prompt>`.
The agent then only sees a truncated prompt and fails with "Workspace Trust
Required" or exits 1 immediately.
When LookPath resolves cursor-agent to a .cmd/.bat launcher and a sibling
cursor-agent.ps1 exists, invoke PowerShell directly with `-File <ps1>` so
Go's os/exec passes each argv as a discrete token. This is exactly what the
.cmd does internally; we just skip the cmd.exe re-tokenisation step.
PowerShell host resolution prefers pwsh.exe (PS 7) on PATH, then
powershell.exe on PATH, and finally falls back to
%SystemRoot%\System32\WindowsPowerShell\v1.0.
Platform-specific code is split via build tags
(cursor_invocation_windows.go / cursor_invocation_other.go) so non-Windows
builds carry no Windows-only dependencies. The lookup is exposed as a
package variable to make the Windows path fully unit-testable without
spawning real PowerShell. Five unit tests cover: passthrough on non-launcher
targets, successful rewrite with a multi-line prompt, .exe direct launch
(skip), missing .ps1 (skip), and missing PowerShell host (skip).
The change leaves macOS / Linux behaviour entirely untouched and stays on
the official cursor-agent launch chain - no node.exe direct invocation, no
prompt mutation, no extra flags.
Closes#1297
Made-with: Cursor
