The only visibility into downloaded data was the whole offline.pmtiles row, and the only delete was "everything" (whole file + whole cache). GET /api/offline-tiles/cache lists what's really in data/geofabrik_cache/ right now — distinct from offline.pmtiles' own meta.sources, which only reflects the last successful build and can disagree with both the current selection and the cache (ticked-but- not-Applied, or built-from-but-since-unticked). The region picker now shows each cached country's size next to its checkbox, with its own delete button (DELETE /api/offline-tiles/cache/:code, already added but unused by the UI until now) — removing just that entry rather than clearing the whole cache.