The backup controller now checks if the PHP ZIP extension is installed and passes this information to the view. The backup page displays a warning if the extension is missing, guiding users to install it for backup and restore functionality.
Introduces user-facing JSON+ZIP export and import for stations, logbooks, and QSOs, including preview and progress views. Updates backup controller to allow all authenticated operators (level 2+) and replaces legacy backup card with new workflow in the UI. Adds new views for import preview and progress, supporting selective import and conflict handling.