Add local command layout helper

[caomengxuan666]

Adds a small PowerShell helper for local development/testing. It creates a per-command layout from a built coreutils.exe without running the installer:

• artifacts\dev-layout\bin\<utility>.exe
• artifacts\dev-layout\cmd\<utility>.cmd

The script uses NTFS hard links first, since they do not require elevation. If hard links are unavailable, it copies the binary by default.

Validation run locally:

.\scripts\create-dev-links.ps1 -Force
.\artifacts\dev-layout\bin\cat.exe --version
.\artifacts\dev-layout\cmd\grep.cmd --version
.\artifacts\dev-layout\bin\find.exe --version

This produced 77 .exe and 77 .cmd entries from the current coreutils.exe --list output, skipping [ to match the existing installer behavior.