Winget manifest submission

[Phoenix-]

Publish Meridian to the winget repository so winget install meridian works.

Scope

• YAML manifest in microsoft/winget-pkgs (installer + locale + version files).
• Automation that bumps the manifest version on each release tag.
• SHA256 hash of signed installer.

Depends on

• Installer (Installer (MSIX) #4) — winget needs a downloadable installer URL.
• Code signing (Code signing #7) — winget requires installer to be signed.
• A public release on GitHub Releases for the manifest to point at.