OfflineStatusBanner

A small pill reporting that the device has no network connection right now.

Purely informational — neither map backend needs this composable to keep rendering offline. MapLibre already serves any tile it holds (an offline pack or its own ambient cache) straight from disk the instant a network fetch fails, and the Google flavor's auto-switch to a local basemap (see MapViewModel.handleConnectivityChange) happens independently of whether this is on screen. It exists only so a blank or stale-looking map reads as "you're offline" rather than as a bug.