[SingularVector]

Summary

Add Test-IsGuid to IT-ToolBox 3.1.0, bringing the standalone GUID validator into the module’s supported API.

Scope

• Port Test-IsGuid from PowerShell-Functions.
• Accept complete GUID strings in N, D, B and P formats.
• Reject whitespace, malformed input and the X initializer format.
• Return one Boolean per pipeline input; null and empty inputs return false.
• Update the manifest, loader, README, changelog and packaging expectations for 30 exported functions.
• Add GUID regression tests.

This is an additive API change with no new dependencies. Existing commands and the PowerShell 7.4+ requirement remain unchanged. The logger fixes from 3.0.1 are retained.

Validation

• Pester tests run — 383 passed, 0 failed, 5 skipped on macOS
• Module imports successfully — including extracted archive validation
• Documentation updated where needed
• No unrelated files changed

Notes

The module archive builds successfully. Windows and Linux validation runs through CI.

Test-IsGuid checks syntax only. The all-zero GUID is valid input; acceptance does not establish that an associated object or resource exists.

This PR prepares 3.1.0 repository content; it does not create a release tag or publish the module.