Co-authored-by: Mikey Lombardi (He/Him) <michael.t.lombardi@gmail.com>

When invoke_command is called with input = None, the child process
previously inherited the parent's stdin handle. In CI environments
where the parent has a redirected pipe for stdin, this caused PowerShell
child processes to block indefinitely on `$Input` (reading from the
inherited pipe that never closes).

The fix sets stdin to Stdio::null() when no input is provided, ensuring
the child process sees an immediate EOF rather than inheriting whatever
stdin handle the parent holds.

Root cause: commit 1af2c8b changed the PowerShell adapter from
"config": "full" to "config": "single", which routes export through a
code path that calls invoke_command with no input. Previously, the
full-config path always provided input so stdin was always piped.

Also adds:
- Integration test that detects this regression in all environments
  (terminal and CI) without leaving hanging threads
- A -RustTestFilter parameter to build.ps1 / Test-RustProject to
  allow running a specific Rust test by name via the build script

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Backport PSScript HadErrors fix and update crates

Backport minor fixes to PSScript resource