feat(misc): broaden CLI version detection to PATH and Windows managers

Extend scan_cli_version search paths with the PATH environment variable
and common Windows Node/version-manager locations (pnpm, Volta, nvm,
Scoop, Yarn). Entries from PATH are skipped when they point at the
Microsoft\WindowsApps App Execution Alias directory, which is what
previously caused bogus launches on Windows.

Add unit tests for PATH dedup, child-dir suffix expansion, and the
WindowsApps alias skip.