[Feature] Test: Add function-level dot-sourcing dependency check

[z-Fng]

Feature Request

Related Issues

• [Bug] Function nightly_version not defined error when running scoop download #6385
• [Bug] Undefined function 'url_filename' encountered when running 'scoop uninstall' #6514

Description

Add static analysis CI that scans PowerShell scripts via AST to detect missing dot-sourced dependencies.
This check ensures all referenced .ps1 files exist before execution, helping prevent runtime errors caused by missing imports.