Rally preview 0.5.0

- Replaced the Add game menu's Windows icon gutter and blue highlight with Rally's charcoal/violet styling.
- Added automatic startup update checks, limited to once a day, with a manual check and opt-out in Connections.
- New versions show an update notice and open the official download in your browser. App files are replaced by the user; library data stays in its existing folder.
- Includes CSV review/import, recursive folder discovery, exact Unicode paths, wrapper/shortcut launch settings, and default-browser Epic/EA sign-in from the previous preview.

This remains an early preview. Real store account sign-ins and game launches require testing with account owners. Xbox full ownership sync and automatic account switching inside original launchers aren't implemented. No game files are included.
