App 2.39.0, server 2.7.0: Grid with map

A new Overview style: the Grid over the roads round the car from
OpenStreetMap, drawn in the floor's perspective, heading up, the bigger
roads glowing brighter, the car as a chevron.

Server: POST /v1/map/roads {z:14,x,y} fetches a tile's drivable roads
from Overpass (OVERPASS_URL; one request at a time, at least a second
apart), simplifies them to tile-local points in four classes, caches
them for 30 days and never logs the tile.

App: MapRoads keeps the 3x3 tiles round the car from its own cache or
the server; GPS only while the style is shown; bearing from the GPS or
from successive positions. Without GPS, server or roads the plain floor
says why. OSM attribution on screen and in LICENSE.md.

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

app/src/main/res/values/strings.xml

@@ -136,6 +136,7 @@
     <string name="overview_style_terminal">Terminal</string>
     <string name="accent_original">Original</string>
     <string name="overview_style_grid">Grid</string>
+    <string name="overview_style_grid_map">Grid with map</string>
     <string name="overview_style_time_circuits">Time circuits</string>
     <string name="overview_style_quest">Quest</string>
     <string name="overview_style_visor">Visor</string>