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

server/api.go

@@ -20,6 +20,7 @@ import (
 //	GET  /v1/health                              unauthenticated liveness probe
 //	     /v1/settings/…, /settings                settings typed on a phone (handoff_http.go)
 //	GET  /v1/app/…                               app updates from the forge (releases.go)
+//	POST /v1/map/roads                           the roads of one map tile (maps.go)
 //
 // A car authenticates with the shared INGEST_TOKEN or with its own token from pairing
 // (pairing_http.go).
@@ -31,6 +32,8 @@ type API struct {
 	Handoff *Handoff
 	// Releases relays the app's releases from the private forge to the car (releases.go).
 	Releases *Releases
+	// Maps serves the roads for the Overview's map from OpenStreetMap (maps.go); nil is off.
+	Maps *Maps
 	// PublicURL is the server's address as a phone reaches it, for the pairing QR code;
 	// derived from the request when empty.
 	PublicURL string
@@ -50,6 +53,7 @@ func (a *API) Routes() http.Handler {
 	a.pairingRoutes(mux)
 	a.handoffRoutes(mux)
 	a.releaseRoutes(mux)
+	a.mapRoutes(mux)
 	return mux
 }