Compatibility bridge to v5.8.4 for early test builds

Compatibility update for early ZenState test builds

This is a one-time update bridge for installations labelled 5.8.4-test. It directs their existing updater to the verified ZenState v5.8.4 stable release.

The application installed is 5.8.4, with exactly the same installers and checksums as the stable release. This prerelease contains only compatibility metadata; it is not a different application build. Once updated, ZenState follows the stable channel normally.

Finish and save any running timer before updating from an older version.

For manual installation and the full list of improvements, use the v5.8.4 stable release linked above.