cleanup: drop coord backfill, drop transit overlay, block PM autofill

- Remove the admin "Koordinaten nachladen" button, /actions/backfill-coords
  endpoint, geocode.py, googlemaps dep, GMAPS_API_KEY plumbing in the web
  service, and the map diagnostic line. Going-forward geocoding happens in
  alert on scrape; upsert_flat backfill on re-submit remains for edge cases
- Remove the OpenRailwayMap transit overlay (visually noisy); keep CartoDB
  Voyager as the sole basemap
- Profile + notifications forms get autocomplete="off" + data-lpignore +
  data-1p-ignore at form and field level to keep password managers from
  popping open on /einstellungen; immomio_password uses autocomplete=new-password

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -28,7 +28,6 @@ services:
       - SMTP_PASSWORD=${SMTP_PASSWORD:-}
       - SMTP_FROM=${SMTP_FROM:-lazyflat@localhost}
       - SMTP_STARTTLS=${SMTP_STARTTLS:-true}
-      - GMAPS_API_KEY=${GMAPS_API_KEY:-}
     volumes:
       - lazyflat_data:/data
     expose: