Prepare notarization and public macOS distribution path

[TheGuyWithoutH]

Summary

Define the notarization and distribution path needed for a polished public macOS release.

Why

If the project graduates from unsigned alpha to broader public distribution, notarization and release packaging will be required.

Scope

• Document notarization prerequisites.
• Define release artifacts and install flow.
• Identify which assumptions from the current unsigned alpha need to change.

Acceptance Criteria

• The notarization/distribution path is documented as a concrete follow-up plan.
• Contributors understand the difference between the current alpha and the future polished path.