Fix the macOS release build and let its assets be rebuilt

[EwyBoy]

The macOS job of the 0.6.0.0 release failed with The target "BundleApp" does not exist, so the release went out without the .dmg and the macOS CLI.

build-mac-app.sh ran dotnet msbuild -t:BundleApp without restoring first, so the Dotnet.Bundle package's target was never loaded. PR CI missed it because dotnet test ran before the app build there and had already restored.

• build-mac-app.sh passes -restore. Checked in a clean worktree: the old command reproduces the CI error, the fixed script builds the app and the CLI.
• The release workflow gets a manual trigger that runs the macOS jobs even when the tag already exists. That is how 0.6.0.0 gets its macOS assets once this is merged. The notes step skips adding the macOS section if it is already there.
• PR CI builds the macOS app before running the tests, on an unrestored checkout like the release job, so this cannot slip through again.