- Add data_sources.yaml for configurable data source URLs
- Add data_sources.py to load config with database override support
- Add arcgis_landing_points and arcgis_cable_landing_relation collectors
- Change visualization API to query arcgis_landing_points
- Add /api/v1/datasources/configs/all endpoint
- Update Earth to fetch from API instead of static files
- Fix scheduler collector ID mappings
- Add ARCGIS_CABLE_URL, ARCGIS_LANDING_POINT_URL, ARCGIS_CABLE_LANDING_RELATION_URL to config
- Use @property to read URL from settings in collectors
- URLs can now be configured via environment variables
- Add ArcGISLandingPointCollector for FeatureServer/1 (landing points)
- Add ArcGISCableLandingRelationCollector for FeatureServer/3 (cable-landing relations)
- Register new collectors in __init__.py
- Fix earth cables.js with cable_id grouping for highlight
