Export Format Selector

This is a low-complexity UI widget with no external dependencies, making it straightforward to deliver early in the sprint cycle. The primary planning consideration is keeping the list of available formats and their compatibility notes synchronised with Bufdir's actual current requirements, which may change between reporting cycles. A mechanism for disabling formats via disableFormat(format, reason) provides a lightweight way to surface compatibility changes without a code release, provided the calling screen or configuration layer can supply updated availability data. Testing should verify that format selection state is correctly emitted, that disabled formats display appropriate messaging, and that the widget resets cleanly when re-rendered.

Because this widget has no shared flag, its API surface only needs to satisfy the Bufdir export screen, keeping scope well contained. Estimate a quarter-sprint for implementation.

BufdirExportFormatSelector is a stateless-friendly UI widget targeting frontend and mobile execution contexts. setAvailableFormats(List formats) populates the selectable options at mount time, allowing the parent screen to control which formats are offered based on runtime configuration or feature flags. disableFormat(ExportFormat format, String reason) marks a specific format as unavailable with a human-readable explanation rendered inline, useful for deprecating a format or signalling a temporary backend limitation without removing the option from the UI entirely. onFormatSelected(ExportFormat format) is a callback prop that fires immediately on user interaction, and getSelectedFormat() provides synchronous read access for imperative callers.

The ExportFormat enum should be defined in a shared types module to avoid duplication between this widget, the export trigger screen, and the backend service layer. Consider persisting the last-used format selection in local storage so returning users do not need to re-select on every export session. Ensure disabled format items are visually distinct and accessible, with ARIA disabled attributes and sufficient contrast for the reason text.