Rjf/gbfs

[robfitzgerald]

this PR includes the change set required to support GBFS-mode travel.

• downloader CLI
• ETL into records.csv.gz-type format, global identifiers
• constraint + traversal modeling

[robfitzgerald]

example output from downloader tool.

% cd rust
% ./target/release/bambam-gbfs download -g "https://chattanooga.publicbikesystem.net/customer/gbfs/v3.0/gbfs.json" -o out

{
  "info": {
    "last_updated": "2026-07-15T21:27:14Z",
    "ttl": 30,
    "version": "3.0",
    "data": {
      "system_id": "bike_chattanooga",
      "languages": [
        "en",
        "fr",
        "nl",
        "es"
      ],
      "name": [
        {
          "text": "bike_chattanooga",
          "language": "en"
        },
        {
          "text": "bike_chattanooga",
          "language": "fr"
        },
        {
          "text": "bike_chattanooga",
          "language": "nl"
        },
        {
          "text": "bike_chattanooga",
          "language": "es"
        }
      ],
      "opening_hours": "Mo-Su,PH 00:00-24:00",
      "feed_contact_email": "mobility-data-client@lyft.com",
      "timezone": "America/New_York"
    }
  },
  "geofence": {
    "last_updated": "2026-07-15T21:27:14Z",
    "ttl": 30,
    "version": "3.0",
    "data": {
      "geofencing_zones": {
        "type": "FeatureCollection",
        "features": []
      },
      "global_rules": []
    }
  }