winget manifest

[johnnyhuy]

Summary

• Publish winget manifest for Windows installs.

Context

• winget is the default Windows package manager for many users.

Scope

• Create winget YAML manifest with URLs and hashes.
• Document update flow for new releases.

Out of scope

• Automated submission to winget-pkgs (can be manual initially).

Acceptance criteria

• winget install skillet installs the correct binary.