App 2.39.1, server 2.8.0: map roads from OpenFreeMap, on demand

The public Overpass answered 429/502 and needs ~40 s a tile while the
car gives up after 8 s, so the server cancelled its queries and the
car's retries added load. Now the server fetches only the tiles a car
asks for, as OpenStreetMap vector tiles from OpenFreeMap (MAP_TILES_URL),
decodes the transportation layer with a small reader of its own, and
keeps each tile 30 days on a volume (MAP_CACHE_DIR). A fetch finishes
even after the car has stopped waiting; the car hears 503 with
Retry-After and gets the tile on its next try.

App: OpenFreeMap/OpenMapTiles attribution on the map, retry after 15 s.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 142
-        versionName "2.39.0"
+        versionCode 143
+        versionName "2.39.1"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.