Restore osrm-init profile and fix host port mapping

Adds back the osrm-init service (profile: init) used by docker/osrm/update.sh
to extract, partition, and customize CT map data. Also documents that the host
port should be set to match the reverse proxy expectation (e.g. 8660:3000).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -1,4 +1,16 @@
 services:
+  osrm-init:
+    image: osrm/osrm-backend
+    container_name: osrm-init
+    profiles: [init]
+    volumes:
+      - ./docker/osrm/data:/data
+    entrypoint: /bin/sh -c
+    command: >
+      "osrm-extract -p /opt/car.lua /data/connecticut-latest.osm.pbf &&
+       osrm-partition /data/connecticut-latest.osrm &&
+       osrm-customize /data/connecticut-latest.osrm"
+
   osrm:
     image: osrm/osrm-backend
     container_name: osrm