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>

web/db.py

@@ -439,35 +439,6 @@ def get_flat(flat_id: str) -> Optional[sqlite3.Row]:
     return _conn.execute("SELECT * FROM flats WHERE id = ?", (flat_id,)).fetchone()
 
 
-def flats_missing_coords(limit: int = 500) -> list[sqlite3.Row]:
-    return list(_conn.execute(
-        """SELECT id, address FROM flats
-            WHERE (lat IS NULL OR lng IS NULL) AND address IS NOT NULL AND address != ''
-            ORDER BY discovered_at DESC LIMIT ?""",
-        (limit,),
-    ).fetchall())
-
-
-def set_flat_coords(flat_id: str, lat: float, lng: float) -> None:
-    with _lock:
-        _conn.execute(
-            "UPDATE flats SET lat = ?, lng = ? WHERE id = ?",
-            (lat, lng, flat_id),
-        )
-
-
-def count_flats_coords() -> tuple[int, int]:
-    """Return (total_flats, with_coords)."""
-    row = _conn.execute(
-        "SELECT COUNT(*) AS total, "
-        "       SUM(CASE WHEN lat IS NOT NULL AND lng IS NOT NULL THEN 1 ELSE 0 END) AS geo "
-        "FROM flats"
-    ).fetchone()
-    total = int(row["total"] or 0)
-    geo = int(row["geo"] or 0)
-    return total, geo
-
-
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